Handbook of Children’s Literacy || Reading Comprehension Difficulties

C5. Reading Comprehension Difficulties

KATE CAIN & JANE OAKHILL

ABSTRACT

In this chapter we consider the nature and the source of difficulties experienced by children with a specific type of comprehension deficit, children who have developed age-appropriate word reading skills but whose reading comprehension skills lag behind. As discussed elsewhere in this volume, text comprehension is a complex task that involves many different cognitive skills and processes. Consequently, there are many different aspects of the reading process where difficulties may arise, which may, in turn, contribute to these children's poor comprehension. In this chapter, we examine the evidence that impairments at the word-, sentence-, and discourse-level playa causal role in this population's comprehension difficulties. In addition, we consider whether deficits in cognitive abilities such as memory skills and general intelligence, and factors such as amount of exposure to print, contribute to poor comprehension.

INTRODUCTION

A child requires two skills to be a successful and independent reader: They must be able to decode 1 the individual words on the page and they must be able to comprehend the text. Word decoding and reading comprehension are highly related skills: correlations between these skills fall within the range of 0.3 to 0.77 (Juel, Griffith & Gough, 1986; Yuill & Oakhill, 1991). When decoding and reading comprehension difficulties are concomitant, problems with understanding can arise because laboured word decoding leaves the reader with insufficient processing capacity to compute the relations between successive words, phrases, and sentences to construct a coherent and meaningful representation of the text (e.g. Perfetti, 1985). However, accurate decoding skills do not ensure adequate reading comprehension. Approximately 10% of (British) school children have adequate

I In this context, we use the term decoding to refer to word recognition in general, which may be accomplished, for example, by recoding from graphemes to phonemes, by sight recognition, or by analogy (e.g. Ehri, 1999).

313

T. Nunes. P. Bryant (eds), Hamlhook of Children', Literacy, 313-338 ~J 2004 KlulI'er Aradenllc Pubilslzers

314 Kate Cain & Jane Oakhill

decoding skills but poor reading comprehension (Stothard & Hulme, 1996; Yuill & Oakhill, 1991). Furthermore, these children demonstrate a general deficit in text comprehension, performing poorly on assessments of both reading and listening comprehension (Cain, Oakhill & Bryant, 2000a; Stothard & Hulme, 1992). Thus, decoding deficits are not an obvious source of their reading comprehension difficulties. This chapter is concerned with the nature and the source of the text comprehension difficulties (for both written and spoken text) experienced by this particular population, to whom we refer to as less skilled comprehenders.

Text comprehension is a complex task that involves many different cognitive skills and processes. Consequently, there are many different aspects of the reading process where difficulties may arise and which, in turn, affect text comprehension, e.g. word-level, sentence-level and discourse-level. In addition, cognitive abilities such as memory skills and general intelligence, and factors such as amount of exposure to print, may also affect comprehension. In this chapter we assess the evidence that deficits in each of these areas are a source of the problems that less skilled comprehenders have with text comprehension. In using this framework we are not suggesting that language processing takes place within a strictly modular system. We are simply using this categorisation to impose a workable structure on the chapter. Indeed, as will become clear during the course of our review, there is evidence that the processing of verbal information at three different language levels (word, sentence and discourse) can affect performance at another level in both a bottom-up and top-down manner. Another proposal that we explore is the distinction made by Perfetti, Marron and Foltz (1996) that comprehension may be affected by both knowledge and processing skills (e.g. vocabulary and inference making, respectively).

As mentioned above, weak decoding skills can adversely affect reading comprehension performance. Many studies investigating comprehension skills have either used an assessment of reading comprehension that confounds these two variables or have not controlled for individual differences in word reading skill (e.g., Forrest-Pressley & Waller, 1984; Jetton, Rupley & Willson, 1995; Kirby & Moore, 1987; Nation & Snowling, 1999; Paris & Jacobs, 1984; Smith, Macaruso, Shankweiler & Crain, 1989). Therefore, the extent to which such studies address comprehension difficulties rather than just general reading difficulties is unclear. For this reason, we concentrate on studies that have included measures of decoding skill and reading comprehension in this review. If measures of both these components are taken, the influence of decoding on comprehension level can be taken into account when analysing data or decoding skill can be held constant for the populations being studied. The latter procedure, matching groups for decoding skill, has been adopted by us and other researchers in much of the work that we discuss in this chapter (e.g. Yuill & Oakhill, 1991). Typical characteristics of groups from our research are shown in Table 1. As well as the issue of subject selection, there are a number of issues concerning the appropriate experimental design to test causal hypotheses, discussion of which is beyond the scope of this chapter. We refer the interested reader to Cain, Oakhill

Reading Comprehension Difficulties 315

Table 1 The mean scores (and standard deviations) of typical groups

Less skilled Skilled Comprehension comprehenders comprehenders -age match

(N = 14) (N=12) (N=12)

Chronological age 7,7 (4.44) 7,7 (4.04) 6,6 (3.88) Sight vocabulary 37.21 (4.00) 37.42 (3.00) 32.92 (2.91) Word reading accuracy in context 7,9 (5.17) 7,11 (5.73) 6,7 (4.98) Reading comprehension 6,7 (3.87) 8,1 (5.14) 6,8 (3.11)

Note. Where appropriate, ages are given as years, months with standard deviations in months.

and Bryant (2000a) for further details on these issues in relation to reading comprehension.

The structure of the remainder of this chapter is as follows. In the following four sections we review the different potential sources of deficit, as outlined above. In the final discussion section, we relate these findings to a model of text representation and consider directions for future research.

WORD-LEVEL DEFICITS AS A SOURCE OF TEXT COMPREHENSION FAILURE

In this section we review work that investigates whether word-level difficulties are related to higher-level text comprehension deficits.

Speed and automaticity of decoding

Slow or inaccurate word reading may affect comprehension because it uses up limited processing capacity that is necessary for text comprehension processes such as integration (Perfetti, 1985). Identification of poor comprehenders who have accurate word recognition skills does not rule out the possibility that their word processing skills are slower and less efficient than those of good comprehenders. However, in several studies, assessments of word reading speed, automaticity of decoding and accuracy of nonword reading have revealed no differences between skilled and less skilled comprehenders (Oakhill, 1981; Stothard & Hulme, 1996).

Phonological skills

Phonological skills are strongly associated with word reading development (e.g. Bradley & Bryant, 1983; Wagner & Torgesen, 1987) and children with dyslexia commonly experience difficulties with the phonological representations of words (Hulme & Snowling, 1992). Phonological processing deficits have also been posited


as an underlying cause of poor readers' comprehension difficulties in that they impair the reader's ability to retain verbal information in working memory and, thus, complete higher-level processing for meaning (see Shankweiler, 1989, for a review). Shankweiler and colleagues have repeatedly demonstrated differences between good and poor readers' ability to retain and process verbal information in a phonological form. However, this work did not take individual differences in word reading skill into account, so it does not demonstrate a direct relation between comprehension skill and phonological processing.

We know of only two studies that have investigated the relation between phonological processing skill and reading comprehension, whilst controlling for word reading ability (Cain, Oakhill & Bryant, 2000b; Stothard & Hulme, 1996). Both studies failed to find differences between skilled and less skilled comprehenders' performance on a range of tasks that involved the storage of phonological stimuli, and the isolation and manipulation of phonemes. Cain et al. did find a relation between comprehension skill and one phonological assessment, a version of Bradley and Bryant's (1983) odd-word-out task. The authors speculated that the poor comprehenders' difficulties with this task may reflect their weak working memory skills and subsequent work has confirmed that performance on this task is more dependent upon working memory than other phonological awareness tasks (Oakhill & Kyle, 2000). We discuss the relation between memory and comprehension skill in more detail later on.

Vocabulary and semantic knowledge

Word knowledge is highly correlated with reading comprehension ability in both children and adults (Carroll, 1993), but the relation between the two is not clear. Limited vocabulary knowledge does not always impair comprehension (Freebody & Anderson, 1983, but see Wittrock, Marks & Doctorow, 1975) and vocabulary knowledge per se does not appear to be sufficient to ensure adequate comprehension of larger units of text (e.g. Pany, Jenkins & Schreck, 1982). As already noted, several researchers have demonstrated that children can experience text comprehension difficulties even when vocabulary knowledge is controlled for (Ehrlich & Remond, 1997; Oakhill, Cain & Yuill, 1998; Stothard & Hulme, 1992).

Although simple vocabulary knowledge may not be a strong determinant of comprehension skill, individuals who possess a rich and interconnected knowledge base may comprehend text better than those whose representations are sparse. For example, Spilich, Vesonder, Chiesi and Voss (1979) demonstrated that prior knowledge about the topic of a text facilitates reading comprehension. Thus, if word meanings are poorly represented in semantic memory, less information will be accessed and perhaps fewer relations between concepts will be made than if a rich semantic representation for word meaning exists. A study by Nation and Snowling (1998a) found differences between good and poor comprehenders on a measure of semantic fluency: the Word Association subtest from the Clinical


Evaluation of Language Fundamentals-Revised (CELF-R, Semel, Wiig and Secord, 1987). In this test, children have to provide as many category members of a category name (e.g. animals) as possible. Nation and Snowling found that poor comprehenders produced fewer instances than did good comprehenders. In a further study, they compared the priming of words that were related by category but differed with respect to associative strength occurrence in both good and poor comprehenders (Nation & Snowling, 1999). For example, the word pairs "catdog" and "aeroplane-train" are both related by category, but the latter pair cooccurs in texts less frequently than "cat-dog" and, therefore, has a lower associative strength. Good comprehenders showed priming for both types of word pair, whereas poor comprehenders only showed priming for word pairs that had high associative strength as well as a category relation.

It is unclear whether Nation and Snowling's studies demonstrate semantic weaknesses in children with specific comprehension problems, because the good and poor comprehenders were not matched for word reading accuracy or for vocabulary skills. Thus, it is possible that the good comprehenders' superior performance on this task was due to their better word reading and/or vocabulary skills, rather than their superior discourse-level comprehension. Indeed, when skilled and less skilled comprehenders are matched for both word reading accuracy and sight vocabulary, we find that they produce comparable numbers of exemplars in the semantic fluency test (Cain, Oakhill & Lemmon, under review). Therefore, we suggest that limited semantic knowledge may be related to comprehension difficulties in certain populations of less skilled comprehenders but not others.

Whether or not these discrepant findings are due to population differences, it is important to establish the process by which the individual differences in the range and richness of semantic representations may arise in the first place. One plausible mechanism for vocabulary acquisition is to infer the meanings of unfamiliar vocabulary items from context (Daneman, 1988; Nagy, Herman & Anderson, 1985). Another source of variance (and one that may contribute to knowledge differences) is differential exposure to print (e.g. Stanovich, 1993). We shall consider these hypotheses in later sections.

Summary

There is a strong relation between general reading ability and decoding efficiency, phonological skills and vocabulary knowledge. However, children with text comprehension difficulties do not necessarily have deficient decoding skills: some poor comprehenders have fluent and accurate word reading skills. Furthermore, although a phonological processing deficit is a plausible source of the text comprehension difficulties experienced by poor word readers, there is no evidence for a direct relation between the tasks assumed to measure phonological processing and reading comprehension skill. There is some evidence that individual differences in semantic representation are related to comprehension performance, but not all


studies have included vocabulary controls. To date the direction of the relation between these two skills has not been addressed: whether good semantic knowledge is a by-product of experience in reading and understanding text or whether it is (in part) contributing to success in text comprehension. However, there is evidence that individual differences in time spent reading account for differences in the growth of vocabulary knowledge (Echols, West, Stanovich & Zehr, 1996), so this is an important area for future investigations.

SENTENCE-LEVEL DEFICITS AS A SOURCE OF TEXT COMPREHENSION FAILURE

Once words have been recognised and their meanings retrieved, the meaning of the sentence must be established. Knowledge about syntactic constraints can aid this process because knowledge about the meanings and order of the noun and verb phrases may be insufficient to establish who did what to whom in sentences such as the following: "The mouse that scared the elephant was chased by the cat". It is perhaps not surprising then that measures of syntactic awareness correlate with measures of reading ability (e.g. Bowey, 1986a; Siegel & Ryan, 1989). First, we consider the relation between reading comprehension and sentence structure. In the second part of this section we consider the extent to which grammatical and semantic constraints may be related to text comprehension via their influence on word comprehension and word recognition.

Syntactic knowledge

There are two ways in which grammatical knowledge may directly facilitate comprehension. It facilitates the comprehension of sentences such as the example above where semantics might be misleading. It has also been suggested that grammatical knowledge may facilitate the detection and correction of reading errors, thereby enhancing comprehension monitoring (Bowey, 1986b; Tunmer & Bowey, 1984). Not all children with discourse-level comprehension problems demonstrate deficits in syntactic knowledge (Yuill & Oakhill, 1991). However, a study by Stothard and Hulme (1992), using the same measure as Yuill and Oakhill, revealed differences between skilled and less skilled comprehenders. It is important to assess memory skills when investigating sentence understanding. Some studies indicate that memory, rather than knowledge, limitations underlie poor sentencelevel comprehension (e.g. Smith, Macaruso, Shankweiler & Crain, 1989), whereas others do not (Bentin, Deutsch & Liberman, 1990). We also need to consider the nature of the relation between syntactic skills and text comprehension: do good syntactic skills arise through good reading comprehension experience, or are they a pre-requisite for skilled comprehension? The precise relation between syntactic knowledge and comprehension is still open for investigation.


Use of sentence context

This section considers work exploring the relation between comprehension skill and the ability to use sentence context to aid both word comprehension and word reading.

The first piece of evidence that less skilled comprehenders make less use of sentence context when constructing meaning comes from an early study by Oakhill (1983). This study was designed to investigate a particular type of inference, an instantiation, where the reader infers a specific meaning of a common noun from the sentence context. For example inferring that "fish" is most likely a "shark" in the following sentence: "The fish frightened the swimmer". Less skilled comprehenders made fewer instantiations than did skilled comprehenders, suggesting that their local processing of text is less influenced by the semantic content of the sentence.

The context of a sentence may also enable the reader to select the appropriate meaning of an ambiguous word. Gernsbacher and Faust (1991) explored this process in college students, who were classified as either good or poor comprehenders. (The students' word reading skills were not reported, but presumably individual differences in word reading do not influence reading comprehension skill in a population of college students to the extent that they might do in a population of school children.) The students were presented with sentences that provided either a neutral or biasing context for the final word, which could take two meanings, e.g. "he picked up the spade" or "he dug with the spade". The task was to decide whether a target word, "garden", was related to the overall meaning of the sentence. Both good and poor comprehenders made use of the biasing context, which suggests that adults with comprehension difficulties are not deficient in their use of sentence context to guide meaning.

Tunmer and Bowey (1984) proposed that children might use the constraints of sentence structure to supplement basic letter-sound knowledge to facilitate word recognition. We know of only one study that has investigated whether sentence context facilitates poor comprehenders' ability to read words, rather than comprehend them (Nation & Snowling, 1998b). In this study, children heard a non-constraining sentence frame such as "I went shopping with my mum and my __ ". They were then presented with one of two different word types on a computer screen. Some had an exceptional spelling-sound pattern, "aunt" for the example above. Other items were words with a regular pronunciation, such as "cash", that had a neighbour with an inconsistent pronunciation, for this example "wash". Accuracy and reading times were recorded. Good comprehenders benefited more than poor comprehenders from the context for both types of word. Because the sentences were constructed so that the final word was not predictable, it is likely that both syntactic and semantic knowledge contributed to performance in this task. Nation and Snowling conclude that impoverished contextual facilitation skills may adversely affect growth in word reading skill of poor comprehenders. Thus, they may develop into garden-variety poor readers,


with weak decoding and comprehension skills, unable to use their comprehension skills to bootstrap their word reading development.

Summary

These studies suggest that at least some children with specific comprehension problems experience difficulties with sentence structure. Clearly, further studies are necessary to establish whether some poor comprehenders are delayed in their acquisition of particular syntactic structures, and the direction of any link between comprehension and syntactic knowledge.

Less skilled comprehenders are less likely to make use of sentence context to guide their comprehension of common nouns. But adults with weak comprehension skills are able to use a biasing sentence context to guide their interpretation of an ambiguous noun. Further work with children is necessary to determine when and how sentence context affects word comprehension, and the direction of the relation. Finally, there is some evidence that good comprehenders are less likely to use context to aid word recognition. However, it is not known whether this impairment is a source of higher-level comprehension difficulties or a byproduct of them.

TEXT-LEVEL DEFICITS AS A SOURCE OF READING COMPREHENSION FAILURE

The higher-level text-processing skills that we consider are integration and inference making, anaphoric reference, use of discourse-level context, and story structure. We also examine metacognitive knowledge and processes. We have explored these skills in some detail, and find that it is at this level of processing (and knowledge) that differences between good and poor comprehenders are most reliably found. Furthermore, our investigations into some of these areas have begun to address the issue of causality using a comprehension-age match design and training studies. Thus, we are able to draw some conclusions about the most plausible direction of these relations.

Text integration and inference making

Inference making ability is a valuable component skill of reading comprehension. Not all details are explicitly mentioned by the author, so the reader must generate links between different parts of a text and use general knowledge to fill in missing detail, in order to construct an adequate and coherent representation of the text.

Early work by Oakhill revealed that less skilled comprehenders are poor at making inferences when reading or listening to text. Relative to skilled


comprehenders, less skilled comprehenders generate fewer constructive inferences, i.e. inferences which require the reader to integrate information from two different sources (Oakhill, 1982), and they are poor at incorporating general knowledge with information in the text to generate simple inferences (Oakhill, 1984). Memory for the text itself did not appear to be the source of their difficulties in these studies.

In recent work we have investigated whether knowledge deficits are a possible source of the less skilled comprehenders' difficulties, given that this knowledge is crucial for the second type of inference described above (Cain, Oakhill, Barnes & Bryant, 2001). We used a procedure that was developed by Barnes and colleagues (e.g., Barnes & Dennis, 1998) that enabled strict control of individual differences in general knowledge. Children were taught a set of facts about an imaginary planet, called Gan. For example, "The flowers on Gan are hot like fire"; "The ponds on Gan are filled with orange juice". Once this knowledge base had been learned, children were read a multi-episode story and were then asked questions to assess their ability to generate inferences. In order to draw these inferences, children had to incorporate an item from the knowledge base with a premise in the text. Recall of the knowledge base was assessed once more at the end of the story and only responses to inference questions for which the knowledge base item was recalled were included in the final analysis. Even when knowledge was controlled for in this very strict way, less skilled comprehenders generated fewer inferences than did the skilled comprehenders.

Another study (Cain & Oakhill, 1999a) included a comprehension-age match group and, thus, sheds some light on the likely direction of the relation between comprehension skill and inference making. In this study, less skilled comprehenders were significantly poorer than skilled comprehenders at generating two types of inference: those that required them to integrate information between two sentences, and those for which they had to incorporate general knowledge with information provided in the text in order to establish adequate sense. The less skilled comprehenders were also significantly poorer than the comprehension-age match group on the first type of inference. We concluded, therefore, that deficient inference making skills were not the result of inferior reading comprehension skills in general, because the less skilled and comprehension-age match groups were matched on this measure. The less skilled comprehenders' difficulties could not be attributed to poor memory for the text, because recall of verbatim detail from the story was comparable for all groups. Again, there was no evidence that general knowledge was the source of difficulty: When an inference was not made, additional questions revealed that all children had the requisite knowledge to make these inferences. Instead, this result suggests that difficulty with the process of inference making contributes to poor reading comprehension.

Two training studies support this proposed direction of causality. In the first, Yuill and Joscelyne (1988) taught children to make inferences from key "clue" words in deliberately obscure texts. In one story, the text does not state explicitly that the main character was lying in the bath, but this setting can be inferred from words such as "soap", "towel", and "steamy". After training, the children were


tested on similar types of story. The less skilled comprehenders benefited more from the training than the skilled group. In another study, Yuill and Oakhill (1988) trained children to make the same type of lexical inference and also to generate questions to test their understanding. The less skilled comprehenders who had received this training made substantial gains in comprehension on the Neale comprehension sub-test, relative to the skilled comprehenders.

Our work, thus far, has demonstrated that less skilled comprehenders have persistent problems with inference making in both reading and listening comprehension tasks. However, the source of the less skilled comprehenders' inference making difficulties is not clear. There is no evidence that memory for the text and/or general knowledge deficits are a fundamental source of difficulty, although they might well be in other populations. One type of knowledge deficit that has not yet been extensively studied is knowing how to make an inference. The training studies may have been successful because they taught the less skilled comprehenders this skill. Another factor to consider is working memory, the capacity to store and process information simultaneously. Performance on working memory tasks discriminates between good and poor comprehenders and we discuss this factor in the section on cognitive processes.

Anaphoric processing

An anaphor is a linguistic device that maintains referential continuity within a text. An anaphor can be a pronoun, such as "he", and takes its meaning from its antecedent in another (preceding) part of the text. "John" is the antecedent for the anaphoric pronoun "he" in the following: "John was very tired, so he went to bed". Anaphoric links can be made both within and between sentences. Anaphoric resolution is, thus, similar to inference making, in that the reader must make links between different parts of the text to maintain coherence.

Oakhill and Yuill compared skilled and less skilled comprehenders' ability to supply and resolve anaphors in three studies. In the first study (Yuill & Oakhill, 1991, expt. 4.4) children were presented with 2-clause sentences, such as "Peter lent his coat to Sue because she was cold". In this example, the antecedent (Sue) of the anaphor (she) is cued because there is only one female antecedent in the main clause. Less skilled comprehenders were worse at resolving the anaphors overall, whether or not a cue was present. A second experiment (Oakhill & Yuill, 1986) demonstrated that less skilled comprehenders were also poorer than skilled comprehenders at supplying the correct anaphor (either "he" or "she") in sentences such as the following '''Steven gave his umbrella to Penny in the park because _ wanted to keep dry". A final experiment (Yuill & Oakhill, 1988) explored anaphoric reference more generally by using four types of cohesive ties: reference, ellipses, substitutions, and lexical ties. The text used was longer and more naturalistic than the short ones used in the above studies. Again, less skilled comprehenders were poorer at resolving these cohesive ties.


Ehrlich and colleagues have extended this line of research in their exploration of anaphoric processing in French children. Ehrlich and Remond (1997) demonstrated that 9-year-old less skilled comprehenders were generally impaired in resolving both pronoun and general noun anaphors, and had particular difficulty with object pronouns that had distant antecedents. In other studies, this group of researchers has explored the link between anaphoric processing and metacognitive skill (the latter is discussed in detail below).

Ehrlich (1996) compared 13- and 15-year-old skilled and less skilled comprehenders' ability to detect inconsistencies in expository texts. The inconsistencies occurred where nouns with contrasting meanings replaced noun phrase anaphors. Less skilled comprehenders detected fewer of these contradictions than did the skilled group. In a later experiment, Ehrlich, Remond and Tardieu (1999) found that lO-year-old less skilled comprehenders also detected fewer anaphoric inconsistencies.

These studies demonstrate that less skilled comprehenders of different ages have difficulties with anaphoric processing: they are poor at resolving anaphors, supplying appropriate anaphors, and detecting inconsistent anaphors. Clearly a difficulty in establishing anaphoric reference will affect the reader's ability to construct a coherent and integrated representation of the text. A deficit in using these devices may, therefore, lead to text comprehension problems. However, to our knowledge, no studies investigating the direction of the relation between these skills have been undertaken.

Use of context at the discourse-level

In this section we review work that has investigated whether poor comprehenders experience deficits in their ability to use the context of a story to establish meaning.

A recent study explored less skilled comprehenders' ability to use story context to derive the meanings of novel vocabulary items (Cain, Oakhill, & Elbro, in press). Good and poor comprehenders read short texts that contained an unknown (made-up) word, the meaning of which could be derived from information contained in one of the story sentences. This sentence occurred either immediately after the unknown word or later in the story after some additional filler sentences. In general, less skilled comprehenders were poorer at this task than the skilled comprehenders. However, they were particularly impaired on stories where the additional filler sentences separated the occurrence of the unknown word and the helpful sentence context, a condition where the working memory demands of the task were greatest. As mentioned in the section on semantic knowledge, skill in making discourse-level inferences may be an important determinant of vocabulary acquisition (e.g., Daneman, 1988; Jensen, 1980; Sternberg & Powell, 1983). Thus, a weakness in this higher-level ability may affect subsequent vocabulary growth, and lead to lower-level deficits in word level knowledge.


Sometimes a reader may come across a phrase in a text that cannot be interpreted by reference to a single sentence. Instead, he or she must use the overall theme of the text to make sense of it. We have investigated this skill by studying children's ability to determine the meanings of idioms (Cain & Oakhill, 1999b). Idioms are figurative expressions that are often categorised into two types: Transparent idioms, such as "to skate on thin ice", whose meaning can be deduced from the component words, and opaque idioms, such as "to kick the bucket", whose meaning has become obscure and must be learned. Children were presented with short stories that contained an idiom, some of which were novel. For both 8 year olds and 10 year olds we found that skilled comprehenders were more likely than less skilled comprehenders to produce interpretations that were either accurate interpretations of the idioms or a plausible figurative interpretation. The less skilled comprehenders' interpretations of these phrases were less likely to be based on the context of the story as a whole, and included literal interpretations of these phrases that were implausible within the context of the story.

Less skilled comprehenders experience particular difficulty with the use of story context to facilitate understanding of unknown words and phrases in text. This higher-level process may be an important mechanism for acquiring information from context in everyday reading and, thus, impairments in the use of context may affect vocabulary growth. We need to establish whether a deficit in the use of context leads to reading comprehension (and word level) problems or is a result of such difficulties.

Metacognition

In this section we discuss work which assesses the relation between metacognitive aspects of reading and comprehension ability. Metacognition has been defined as "Knowledge about and regulation of cognitive states and processes" (Kurtz, 1991, emphasis added). For example, knowledge about the goals of reading, and the ability to monitor and regulate one's reading to meet the demands of the current task. We shall adopt this distinction in our review.

Knowledge

It is not surprising that younger and poorer readers have limited knowledge about reading, and that they tend to focus on the word reading rather than the meaning construction aspects of the task (Myers & Paris, 1978; Paris & Jacobs, 1984). However, there is some evidence that poor comprehenders place a greater emphasis on word-level aspects of reading, compared to skilled comprehenders (Garner & Kraus, 1981-1982; Yuill & Oakhill, 1991). For example, Yuill and Oakhill (1991) found that less skilled comprehenders regard poor decoding skills as a particularly important indicator of reading difficulties. Skilled and less skilled comprehenders


differ in their knowledge about both the aims of reading and also about how to repair comprehension failures (Cain, 1999). Furthermore, both English and Italian poor comprehenders demonstrate impaired knowledge about which reading strategies are appropriate for different reading situations, e.g. studying or reading for pleasure (Cain, 1999; Pazzaglia, Cornoldi, & de Beni, 1995). Although these studies demonstrate that metacognitive differences are related specifically to comprehension ability, it is not yet clear whether these knowledge differences arise through differential reading experience or whether they (in part) contribute to individual differences in comprehension skill.

Processes

An important comprehension skill is the reader's ability to regulate their reading to the demands of the current task. If an individual realises that their comprehension is inadequate, they can take appropriate steps to remedy the situation although, as noted above, less skilled comprehenders may not always possess the necessary metacognitive knowledge for such action.

A popular method used to assess skill in monitoring one's comprehension is an inconsistency detection task. In this task, children read short texts containing inconsistencies either between different parts of the text, i.e. conflicting information given in two sentences, or between information given in the text and external information, such as general knowledge. Oakhill, Hartt and Samols (1996) found that less skilled comprehenders were less accurate than skilled comprehenders in detecting nonsense words and anomalous phrases in short narratives. In a second experiment, the less skilled comprehenders were also poorer at detecting pairs of sentences that were contradictory. The difference was more pronounced when the contradictory sentences were separated by filler text, which the authors attribute to individual differences in working memory capacity. This study indicates a processing difficulty for less skilled comprehenders.

Ehrlich's studies on anaphoric processing (Ehrlich, 1996; Ehrlich, Remond, & Tardieu, 1999) suggest that skilled comprehenders may have lacked knowledge about how to repair comprehension failure. For example, the skilled comprehenders not only spent longer reading the inconsistent parts of the text, but they were more likely to look back to the preceding text when an inconsistency was encountered. Ehrlich, Remond and Tardieu (1999) found that the less skilled comprehenders' evaluations of their understanding indicated that they were aware to some extent of their difficulties with these texts. Other work (Cataldo & Oakhill, 2000) also indicates that strategy knowledge may play a role. In this study, Italian school children were required to look back through narrative texts to locate the answers for particular questions. The search strategies that they used were recorded. Less skilled comprehenders used less sophisticated strategies for locating information. For example, they would begin their search at the beginning of the narrative, rather than starting at the paragraph that contained the answer.


There is also a relation between reading comprehension skill and the ability to regulate reading style for different reading goals (Cain, 1999). This study included a comprehension-age match group in order to assess the most plausible direction of any relation between these two skills. Children read short stories under different instruction conditions, such as "skim read" or "read to study". Both the skilled comprehenders and the comprehension-age match group adapted their reading to the instructions, reading more quickly in the "skim read" condition than in the "study" condition. Furthermore, as predicted, their comprehension of the text was poorest in the "skim read" condition and best in the "study" condition. Neither reading speed nor comprehension of the stories was affected by instruction condition for the less skilled comprehenders. The differences found between the less skilled comprehenders and the comprehension-age match group indicate that the ability to set and reach suitable reading targets is not simply a by-product of reading comprehension level. We interpret these findings as evidence that the ability to adapt reading in different situations may be one source of the less skilled comprehenders' general text comprehension difficulties. We have administered tests of comprehension monitoring to the cohort participating in our longitudinal study (Oakhill, Cain & Bryant, in press). We find that a child's performance on this measure when aged 8 years predicts their general reading comprehension ability a year later. Thus, there is some evidence that this skill is necessary for growth and development of comprehension skills.

Less skilled comprehenders are poor at monitoring their understanding of both narrative and expository text. Their ability to search through text and to regulate their reading style is also poor. Furthermore, there is some indication that their knowledge about reading and repair strategies is inadequate. The extent to which knowledge and processing deficits interact warrants further investigation. However, there is some evidence that a weakness in the latter skill may contribute to comprehension difficulties.

Story structure knowledge

Knowledge about the organisation of texts increases throughout middle childhood, although the majority of studies have concentrated on narrative texts (e.g., Stein & Glenn, 1982). Children's recall of stories indicates that tacit knowledge of the structural importance of story units is related to general reading ability (Smiley, Oakley, Worthen, Campione & Brown, 1977). Perfetti (1994) proposes that a possible source of comprehension failure is inadequate knowledge about text structures, which may arise because of insufficient reading experience.

Several studies have found that less skilled comprehenders demonstrate poorer awareness of text structure than do skilled comprehenders. Yuill and Oakhill (1991) presented skilled and less skilled comprehenders with stories, either aurally or in picture form. The task was to select the main point of the story from a choice of four statements, the others being the main setting, the main event, and


an incorrect main point. Less skilled comprehenders were poor at selecting the main point of the story in both presentation conditions. In another study, they investigated the connectives that children included in stories that they either retold (after the experimenter), or narrated from picture sequences. In the retelling task, less skilled comprehenders and skilled comprehenders produced comparable numbers of the connectives that appeared in the original version, but the skilled comprehenders were more likely to include additional connectives. When required to narrate the story told by a picture sequence, less skilled comprehenders produced fewer causal connectives and used referential ties ambiguously. Thus, less skilled comprehenders have difficulties with elements of cohesion that make a story well structured and integrated. Less skilled comprehenders also demonstrate weaknesses with other aspects of text structure. Using a production task, Cain and Oakhill (1996) assessed the structural quality of stores narrated from topic prompts, such as "Pirates", and also picture sequences. When given the topic prompt, less skilled comprehenders produced more poorly organised stories than both skilled comprehenders and a comprehension-age match group. However, their stories were better integrated when narrated from the picture sequence. A later study (Cain, in press) replicated this earlier finding and demonstrated that less skilled comprehenders can also benefit from a title that states the overall direction or point of the story, e.g. "How the pirates lost their treasure".

Several points arise from these studies. First, poorer performance by the less skilled comprehenders, relative to the comprehension-age match group, indicates that the ability to produce structured coherent stories does not simply arise from good reading comprehension experience. Rather, a deficit in this skill is more plausibly associated with the causes of poor comprehension. Second, less skilled comprehenders are able to tell coherent stories when given appropriate help. This finding is supported by a study that assessed skilled and less skilled comprehenders' understanding of abstract stories (Yuill & Joscelyne, 1988). When provided with a title that described the main point of the abstract story, less skilled comprehenders benefited more than did the skilled comprehenders.

Other work has demonstrated a relation between comprehension skill and children's knowledge about the information carried by particular features of text, namely story titles, beginnings and endings. Cain (1996) found that less skilled comprehenders were poor at explaining the types of information that are found in story titles. More than 80% of skilled comprehenders could give appropriate examples of the sort of information contained in a story title, such as "tells you what its about and who's in it", whereas less than one quarter of the less skilled comprehenders were able to do so. The latter group were more likely to respond that a title "tells you whether you like the story or not" and some stated that titles do not tell the reader anything at all! Less skilled comprehenders were also the least aware that the beginnings of stories might contain important information about settings and characters. This work indicates that they have less explicit awareness about these textual features, which can be useful aids for the reader, helping them to invoke relevant background information and schemas.


This work demonstrates that less skilled comprehenders have impaired sensitivity to the function of different parts of a story. In addition, they are poor at comprehending and producing stories unless given support in the form of integrated picture sequences and titles. There is some evidence to suggest that some aspects of story knowledge and the ability to structure stories are determinants of reading comprehension skill. As yet, we cannot state whether the differences found between skilled and less skilled comprehenders arose from processing or knowledge differences. The support provided by picture sequences and goal-directed titles may have freed up useful processing resources enabling the less skilled comprehenders to plan more integrated stories and/or to use a variety of connectives. On the other hand, less skilled comprehenders may have inadequate knowledge about the function of particular connectives, and also story structure and story schemas, knowledge which the helpful prompts may have provided. However, although less skilled comprehenders are poor at explaining the information contained in a variety of textual features, they clearly have some tacit awareness of such cues, benefiting from integrated and goal-directed titles in comprehension and production tasks.

Summary

Less skilled comprehenders experience difficulties with a wide-range of text-level comprehension skills: inference making, anaphoric processing, structuring stories, metacognitive knowledge and monitoring skills, use of context at the discourselevel. There is some evidence that deficits in first four areas might lead to general text-level comprehension difficulties. Such findings need to be followed up by training studies which, if successful, would provide ways to remediate some of the difficulties experience by less skilled comprehenders.

COGNITIVE PROCESSES

Memory skills

In order to understand prose, the reader must be able to hold information in memory whilst computing the relations between successive words and sentences in order to construct a coherent, integrated representation of the text.

Short-term memory

There is little evidence that the ability to store information in short-term memory is related to specific comprehension difficulties. Less skilled comprehenders' recall of


strings of words or digits is comparable to that of their skilled peers (Oakhill, Yuill & Parkin, 1986; Stothard & Hulme, 1992). However, other research suggests that less skilled comprehenders' may have a very selective impairment in the passive storage of verbal information.

Nation, Adams, Bowyer-Crane, and Snowling (1999) found that good and poor comprehenders' recall of concrete nouns (e.g., tooth, fruit) was comparable, but that less skilled comprehenders were poorer when the items to be recalled were abstract (e.g., luck, pride). They conclude that the poor comprehenders' impairment is a reflection of underlying semantic weaknesses. Whereas the good comprehenders were aided by both phonological and semantic representations of the items to be recalled, the poor comprehenders had impoverished semantic knowledge and were thus at a disadvantage when they had to remember certain stimuli, such as abstract words. This restriction in short-term memory could affect later processing and, therefore, lead to text-level deficits. This hypothesis is certainly interesting, and warrants further exploration, but there is an alternative explanation of these findings that should first be ruled out. Nation et al. did not match their good and poor comprehenders for word knowledge (neither word reading accuracy nor vocabulary). Thus, the poor comprehenders that they studied may have had poorer phonological representations of the abstract words because they had weaker word recognition and vocabulary skills, which could have resulted in storage and recall difficulties.

Working memory

As mentioned previously, the reader (or listener) must generate links between different sentences and ideas in order to construct an integrated representation of a text. To achieve this objective, information must be held in memory whilst concurrently carrying out processing operations, i.e., storing the information from one sentence whilst reading the next one. This more active function of memory is known as working memory.

Daneman and Carpenter (1980, 1983) developed the Reading Span Test to measure working memory capacity. The task requires the individual to read and understand a series of sentences (the processing component) whilst concurrently remembering the final word from each sentence (the storage component). Performance on this task is significantly correlated to college students' comprehension skill. Yuill, Oakhill and Parkin (1989) demonstrated that lessskilled comprehenders are poorer on working memory tasks relative to skilled comprehenders (even tasks that require the processing of numbers and not sentences). They propose that this impairment in the ability to store and process information simultaneously may account for the less-skilled comprehenders' difficulties in resolving anomalies and generating inferences from text. Two recent studies have demonstrated that children's reading comprehension skill is specifically related to the processing and storage of verbal material: comprehen-


sion level was not related to performance on spatial working memory tasks (Nation et at., 1999; Seigneuric, Ehrlich, Oakhill, & Yuill, 2000).

As mentioned above, Nation and colleagues propose that the memory limitations found in their population of poor comprehenders reflect underlying semantic weaknesses. Another possibility, originally proposed by Gernsbacher (e.g., Gernsbacher, Varner & Faust, 1990), is that limitations arise from difficulties in inhibiting irrelevant information. For example, Gernsbacher and colleagues found that adult poor comprehenders had trouble in rejecting the inappropriate meaning of an ambiguous word. Good comprehenders were quick to reject such meanings. Another group of researchers working with adult good and poor comprehenders have found that the poor comprehenders often erroneously recalled items from previous trials (de Beni, Palladino, Pazzaglia, & Cornoldi, 1998). The relation between inhibition and comprehension skill needs to be explored in relation to children's comprehension problems.

Although working memory limitations are related to comprehension impairments, it still not clear how the working memory difficulty arises, and which aspects of the task are affected. Furthermore, the work reported so far does not address the issue of whether working memory limitations are a cause or a consequence of reading comprehension difficulties. Studies that have included a comprehension-age match have not ruled out the possibility that working memory differences are the result of differential reading experience, rather than causally related to comprehension skill (Cain, 1994; Stothard & Hulme, 1992). Indeed, Tunmer (1989) has proposed that practice at representing and manipulating linguistic information may facilitate working memory ability.

Verbal ability

In adult populations, reading comprehension skill is related to verbal IQ (e.g. Sternberg & Powell, 1983). Stothard and Hulme (1996) found that children who were less skilled comprehenders obtained low verbal IQ scores relative to their performance IQ. They conclude that less skilled comprehenders have a specific deficit in their verbal skills. We gave the same assessments to similarly selected groups of skilled and less skilled comprehenders (Cain, Oakhill & Bryant, 1999). Like Stothard and Hulme's sample a significant difference between the groups was only evident on the verbal IQ measure. However, the less skilled comprehenders' mean pro-rated verbal IQ score was 97, which is within the "average" range. Other recent work indicates that deficits in verbal intelligence alone cannot completely explain variance in reading comprehension. Oakhill, Cain and Bryant (in press) found that particular comprehension skills such as inference making, comprehension monitoring, story structuring ability, and working memory capacity, predicted variance in reading comprehension skill, even after verbal intelligence scores and vocabulary had been accounted for.

A general assumption is that adequate levels of intelligence are necessary for


good comprehension skills to develop. Alternatively, good comprehension may lead to better performance on measures of IQ. It is important to determine the direction of the relation between reading comprehension and verbal IQ, because it may affect our approach to remediation of comprehension difficulties. Indeed, there is some evidence for the second proposal: Stanovich (1993) has shown that reading experience can foster growth in general verbal ability. Perhaps greater experience in reading and understanding text develops vocabulary knowledge and skills such as inferencing and integration skills, which may facilitate performance on IQ tests. It is plausible, therefore, that a reciprocal relation exists: an individual requires a basic level of intelligence to be able to read and comprehend text, but experience and practice in comprehension skills may then lead to IQ gains.

Exposure to print

As stated in previous sections, inadequate knowledge about semantics, text structure, reading strategies etc. may arise because of insufficient reading experience. Differences in reading experience will also lead to differences in children's experience of processes important for comprehension, such as working memory, use of context, inference making etc. Several studies have found a relation between children's reading comprehension and the time they spend reading (Anderson, Wilson, & Fielding, 1988; Cipielewski & Stanovich, 1992; Taylor, Frye, & Maruyama, 1990). Cunningham and Stanovich (1997) have found that exposure to print accounted for unique variance in grade 11 reading comprehension even after earlier reading comprehension skill had been taken into account. Thus, experience with print can predict later comprehension skill, over and above initial comprehension level.

It is likely that mechanisms such as use of context, inference making skill, and comprehension monitoring, share variance with initial comprehension skill. Thus, the amount and type of practice a child gets may be important for growth in these areas, and also comprehension in general, in addition to skill proficiency at an early age. The amount of time engaged in reading will determine the amount of experience a child has with comprehension skills, which may help to strengthen these skills and make their use more automatic. Time spent reading will also affect the likelihood that the reader will come into contact with a range of vocabulary and text genres.

We have found that 7-8-year-old skilled and less skilled comprehenders matched for word reading accuracy do not differ on a measure of print exposure (Cain, Oakhill & Bryant, 2000a). That finding does not rule out the possibility that these groups may differ in their reading experience as they grow older. Presumably, children with poor comprehension skills derive less pleasure from reading, thus the extent to which they engage in reading as a pastime may reduce over the years, relative to that of peers with initially good comprehension skills.


Thus, we would predict that groups of skilled and less skilled comprehenders who were originally matched for word reading and vocabulary skills may differ on these measures later in time, with less skilled comprehenders becoming "gardenvariety" poor readers (see also Nation and Snow ling, 1998b). However, a more complicated pattern may emerge. Stanovich (1993) reports work with adults who exhibited a discrepancy between their print exposure and reading comprehension ability. He found that individuals with high levels of reading experience but relatively poor comprehension skills actually did better on a measure of receptive vocabulary than did good comprehenders who read little, and that the two groups were comparable on several other verbal cognitive measures. These data suggest that experience with print can, in part, compensate for modest comprehension skill.

However, once differences in word reading skill are apparent, differences in comprehension may be further increased. Better readers will engage with texts that have more difficult and less frequent vocabulary, more difficult syntactic constructions, and more complex text structures. For this reason, it is important to ensure in studies investigating causes of comprehension failure that skilled and less skilled comprehenders are initially matched for their contextual word reading abilities.

Summary

There is little evidence that populations with specific comprehension deficits experience difficulties with the simple storage of verbal information, but it is apparent that they have limitations in their ability to store and process simultaneously. The source of these difficulties, possibly semantic deficiencies or weak inhibition skills, remains to be established. Furthermore, the direction of the relation between working memory and reading comprehension is not yet clear. There are indications that another posited source of comprehension problems, general verbal ability, cannot fully account for comprehension skill deficits. In addition, evidence from adult populations indicates that this skill may interact reciprocally with reading comprehension over time. Differential exposure to print may provide differential opportunities to practice text comprehension skills and, thus, be an important factor in reading development.

CONCLUSIONS

This chapter was concerned with the nature and source of the difficulties experienced by children who have delayed reading comprehension in the presence of adequate word reading and vocabulary. These children experience deficits with many types of knowledge and processes that are important to reading. Their problems are most reliably found on tasks that assess text-level comprehension


skills, such as inference making, anaphoric processing, comprehension monitoring, the use of discourse-level context, and knowledge and use of story structure. The results from both training studies and those adopting a comprehension-age match design indicate that deficits in both inference making ability and story production may be causally linked to text comprehension difficulties. Further work is necessary to establish the likely direction of the relation between other text-level skills and reading comprehension ability.

As well as the text-level difficulties experienced by less-skilled comprehenders, impairments in the use of sentence-level context and some syntactic structures have also been reported. Although some researchers report word-level semantic deficits, others do not, and it may be the case that these discrepancies reflect population differences, such that different populations of poor comprehender experience different fundamental weaknesses. Currently, the extent to which children with text-level reading comprehension difficulties also experience deficits at the word and/or sentence level is not known. Further work is necessary to establish whether and how such impairments may be related to text comprehension difficulties in general. In addition, we need to determine the direction of causality between such weaknesses and inadequate comprehension. For example, semantic deficits may lead to text level comprehension difficulties or, alternatively, inadequate text processing skills may impair the acquisition and richness of semantic representations.

The picture that emerges of less skilled comprehenders from the studies we have reviewed is of children who are able to integrate information locally in a text, but who are not able to produce a coherent Mental Model (see 10hnsonLaird, 1983) of the text as a whole. Such problems are apparent in both their understanding and their production of stories - they do not seem to be able to plan a globally coherent story, but can produce locally coherent text. Thus, such children could be characterised as lacking a "drive for coherence" in both comprehension and production of text. It is not, at the moment, clear what underlies this inability to produce causally linked and well-integrated text models. It may be that less-skilled comprehenders know less about, or are less willing to use, strategies in comprehension. Or, it may be that the strategies that they try to use to build integrated models are less effective than those of skilled comprehenders, perhaps because of some fundamental differences in information-processing ability between the groups.

When investigating comprehension failure, we should also be aware of the limitations of experimental comparisons between skilled and less skilled comprehenders. As Cornoldi, de Beni, and Pazzaglia (1996) point out, such studies do not establish whether less skilled comprehenders in general present a particular deficit or whether every less skilled comprehender presents that deficit. They looked at the performance of 12 less-skilled comprehenders on a range of different comprehension-related tasks. Different children exhibited different profiles of skill strength and deficit. For example, one child demonstrated metacognitive deficits but no working memory deficits, whilst another demon-


strated working memory deficits but no metacogmtlve deficits, although the majority were impaired on some of the assessments of these two skills. Given the number of cognitive skills associated with good reading comprehension, it would be surprising (and discouraging from a remediation point of view) if all the abilities associated with good reading comprehension were deficient in all less skilled comprehenders. Cornoldi et al.'s analysis suggests that the population of children with comprehension difficulties is far from homogenous. It may be that different types of poor comprehender exist: some may have a fundamental weakness in working memory that restricts their ability to make inferences, whilst others may have the necessary working memory capacity to perform such tasks, but lack the relevant metacognitive and strategic knowledge. Thus, different children may fail to construct coherent representations of text because of different underlying impairments.

As this review has demonstrated, we have now established many areas in which children with text-comprehension difficulties demonstrate weaknesses. Work investigating the causal relation between comprehension skill and these deficits is still in its infancy. However, given the range of knowledge and processing problems associated with poor comprehension, and the complex nature of the reading comprehension task itself, it is likely that different children will experience different patterns of deficit.

REFERENCES

Anderson, R. c., WIlson, P. T.. and Fleldmg, L. G. (1988). Growth m readmg and how chIldren spend theIr time outSIde of school. Readmg Research Quarterly. 13. 285-303.

Barnes. M. A. & Dennis, M. (1998). Discourse after early-onset hydrocephalus' Core deficIts m chIldren of average intelligence. Brain and Language. 61, 309-334.

Bentin, S., Deutsch. A .. & LIberman 1. Y. (1990). SyntactIc competence and reading ablhty m chIldren. Journal oj Experimental Child Psychology. 48.147-172.

Bowey, J. A. (l986a). Syntactic awareness and verbal performance from preschool to fifth grade. Journal oj Psycholinguistic Research. 15. 285-306.

Bowey. J. A. (l986b). Syntactic awareness m relation to readmg skill and ongomg comprehenSIon monitoring. Journal of Expenmental ChIld Psychology. 41, 282-299.

Bradley. L. & Bryant. P. E. (1983). Categorising sounds and leammg to read A causal connexlOn. Nature. 301. 419-421.

Cain, K. (1994). An mvestigatlOn mto comprehenSIOn difficultIes in young children Unpubhshed D.Phll. theSIS. University of Sussex.

Cam, K. (1996). Story knowledge and comprehenSIOn skill. In C. Comoldl & 1. V Oakhlll (Eds ). Reading ComprehenSIOn Difjlculties Processes and RemedzatlOn (pp. 167-192). Mahwah. N1. Lawrence Erlbaum AssocIates.

Cam, K. (1999). Ways of readmg: How knowledge and use of strategies are related to readmg comprehenSIOn. Bntlsh Journal of Developmental Psychology. 17. 293-309.

Cam, K. (in press). Text comprehenSIOn and its relation to coherence and coheSIOn m chIldren's fictIOnal narratives. British Journal of Developmental Psychology.

Cain, K. & Oakhill. J. (1996). The nature of the relationshIp between comprehenSIOn skill and the ability to tell a story. British Journal of Developmental Psychology. 14. 187-201


Cain, K. & Oakhill, J. V. (1999a). Inference making and its relation to comprehensIOn failure. Reading and Writing. An Interdisciplinary Journal, 11, 489-503.

Cam, K. & Oakhlll, J.(l999b). "Comprehension skill, context, and the interpretation of figurative language." Paper presented at the sixth annual meeting of the Society for the Scientific Study of Reading, Montreal, April 1999.

Cain, K., Oakhill, J. V .. & Bryant, P. E. (1999). "Reading comprehension failure: Profiles of individuals from different populations. "Paper presented at the 1999 biennial meeting of the Society for Research mto Child Development, Albuquerque, April 1999.

Cam, K., Oakhill, J. V., & Bryant, P. E. (2000a). Investigating the causes of reading comprehensIOn failure' The comprehension-age match design. Reading and Writing. An Interdisciplinary Journal, 12, 31-40.

Cain, K., Oakhill, J. V., & Bryant, P. E. (2000b). Phonological skills and comprehension failure: A test of the phonological processing deficit hypothesIs. Reading and Wrlfing. An Interdisciplinary Journal, 13, 31-56.

Cain, K., Oakhill, J., & Elbro, C. (in press). The ability to learn new word meanings from context by school-age children with and without language comprehension difficulties. Journal of Child Language.

Cain, K., Oakhill, J. V., & Lemmon, K. (under review). Individual differences in the inference of word meanings from context: the influence of reading comprehension, vocabulary knowledge, and memory capacity.

Cain, K., Oakhill, J. V., Barnes, M. & Bryant, P. E. (2001). Comprehension skill, inference making ability and their relation to knowledge. Memory and Cognition, 29, 850-859.

Carroll, J. B. (1993). Human Cognitive Abilities: A Survey of Factor-Analytic Studies. New York: Cambndge University Press.

Cataldo, M. G., & Oakhill, J.V. (2000). Why are poor comprehenders ineffiCient searchers? An mvestlgation mto the effects of text representation and spatial memory on ability to locate information in a text. Journal of Educational Psychology, 92, 791-799.

Clpielewski, J., & Stanovich, K. E. (1992). Predicting growth in reading ability from children's exposure to print. Journal of Experimental Chtld Psychology, 54, 74-89.

Cornoldi, c., De Beni, R., & Pazzaglia, F. (1996). Profiles of reading comprehension difficulties: An analysis of smgle cases. In C. Cornoldi and J. Oakhill (Eds.), Reading comprehenSIOn difficulties Processes and interventions (pp. 113-136). Mahwah, NJ: Lawrence Erlbaum Associates.

Cunningham, A. E., & Stanovich, K. E. (1997). Early reading acquisition and its relation to reading experience and ability 10 years later. Developmental Psychology, 33, 934-945.

Daneman, M. (1988). Word knowledge and reading skill. In M. Daneman, G., MacKmnon, & T. G. Waller (Eds.), Reading research' Advances in theory and practice, vol. 6 (pp. 145-175). San Diego, CA, US: Academic Press.

Daneman, M., & Carpenter, P. A. (1980). Individual differences in working memory and reading. Journal of Verbal Learning and Verbal Behavior, 19, 450-466.

Daneman, M., & Carpenter, P. A. (1983). Individual differences in integrating information between and within sentences. Journal of Experimental Psychology- Learning, Memory and Cognition, 9, 561-584.

De Beni, R., Palladino, P., Pazzagha, F., & Cornoldi, C. (1998). Increases in mtrusion errors and working memory deficit of poor comprehenders. Quarterly Journal of Experimental Psychology Human Experimental Psychology, 51A, 305-320.

Echols, L. D., West, R. F., Stanovich, K. E., & Zehr, K. S. (1996). Using children's literacy activities to predict growth in verbal cognitive skills: A longitudinal mvestigation. Journal oj EducatIOnal Psychology, 88, 296-304.

Ehri, L. C. (1999). Phases of development in learning to read words. In J. Oakhill & R. Beard (Eds.), Reading Development and the Teaching of Reading (pp 79-108). Oxford, UK: Blackwell.

Ehrlich, M. F. (1996). Metacognitive momtoring in the processing of anaphoric devices in skilled and less skilled comprehenders. In C. Cornoldi & J. V. Oakhill (Eds.), Reading Comprehension Difficulties Processes and Remediation. (pp. 221-249). Mahwah, NJ: Lawrence Erlbaum Associates.

Ehrlich, M. F., & Remond, M. (1997). Skilled and less skilled comprehenders: French children's


processing of anaphonc devices m written texts. British Journal of Developmental Psychology. 15.291-309.

Ehrlich, M. F., Remond M., & Tardieu, H. (1999). Processmg of anaphonc devices in young skilled and less skilled comprehenders: Differences m metacogmtive momtoring Readl11g and Wruing. An Interdisciplinary Journal, 11, 29-63.

Forrest-Pressley, D. L., & Waller, T. G. (1984). Cognition. MetacogllltlOll, and Readlllg New York" Springer Verlag.

Freebody, P., & Anderson, R. C. (1983). Effects on text comprehension of differing proportIOns and locations of difficult vocabulary. Journal oj Reading BehaVIOr, 15, 19-39.

Garner, R., & Kraus, C. (1981-1982). Good and poor comprehender differences m knowmg and regulating reading behaVIOrs. Educational Research Quarterly, 6, 5-12

Gernsbacher, M. A., & Faust, M. (1991). The mechanism of suppression: A component of general comprehension skill. Journal of Experimental Psychology Learning, Memory and CognitIOn, 17.245-262.

Gernsbacher, M. A., Varner, K. R., & Faust, M. (1990). Investigating differences in general comprehension skill. Journal of Experimental Psychology. Learlllng, Memory and CognitIOn, 16, 430-445.

Hulme, C. & Snowling, M. (1992). Deficits in output phonology: A cause of readmg failure? Cogllltil'e Neuropsychology, 9, 47-72.

Juei, C., Griffith, P. L., & Gough, P. B. 1986). Acquisition of literacy: A longitudmal study of children m first and second grade. Journal of Educational Psychology, 78, 243-255.

Jensen, A. (1980). Bias III Mental Testing. New York: Free Press. Jetton, T. L., Rupley, W. H., & Willson, V. L. (1995). ComprehensIOn of narrative and expository texts:

The role of content, topic, discourse, and strategy knowledge. In Hmchman, K. A., Leu, D. J., & Kinzer, C. K. (Eds.) Perspectives on ltteracy research and practice. Forty-jourth yearhook ot the national reading conference (pp. 197-204). Chicago: International Readmg Conference.

Johnson-Laird, P. N. (1983). Mental Models. Cambridge: Cambndge Umverslty Press. Kirby, J. R., & Moore, P. J. (1987). Metacognitive awareness about readmg and ItS relatIOn to readmg

ability. Journal oj Psychoeducational Learning, 2, 119-137. Kurtz, B. E. (1991). Cogmtive and metacognitive a~pects of text processmg. In G Denhlere and J.-P.

Rossi (Eds.), Text and Text Processing (pp. 77-103). North Holland: ElseVier. Myers, M., & Paris, S. G. (1978). Children's metacogmtive knowledge about rcadmg. Journal of

Educational Psychology, 70, 680-690. Nagy, W. E., Herman, P. A., & Anderson, R. C. (1985). Learmng words from context, Readl11g Research

Quarterly, 20, 233-253. Nation, K. & Snowling, M. J. (I 998a). Semantic processing and the development of word-recognitIOn

skills: evidence from children with reading comprehensIOn difficulties. Journal of Memory and Language, 39, 85-1O\.

Nation, K. & Snowling, M. J. (I 998b). IndiVidual differences in contextual faCilitatIOn' eVidence from dyslexia and poor readmg comprehenSIOn. Child Development, 69, 996-1011.

Nation, K. & Snowling, M. J. (1999). Developmental differences m senSItivity to semantic relations among good and poor eomprehenders: evidence from semantic primmg COgllltlOIl, 70,81-83.

Nation, K., Adams, J. W., Bowyer-Crane, C. A., & Snowling, M. J. (1999). Workmg memory defiCits m poor comprehenders reflect underlying language impairments. Journal ot Experimental Child Psychology, 73, 139-158.

Oakhill, J. V. (1981). ChIldren's Readmg ComprehenSIOn. Unpublished D.Phll. Thesis. Umverslty of Sussex.

Oakhlll, J. V. (1982). Constructive processes in skilled and less- skilled comprehenders' memory for sentences. British Journal of Psychology, 73, 13-20.

Oakhill, J. V. (1983). Instantiation in skilled and less-skilled comprehenders. Quarter(l' Journal of Experimental Psychology, 35A, 441-450.

Oakhill, J. V. (1984). Inferential and memory skills m children's comprehenSIOn of stones. British Journal of EducatIOnal Psychology, 54,31-39.

Reading Comprehension D(fficulties 337

Oakhill, 1.V. & Kyle, F. (2000). The relation between phonological awareness and working memory. Journal of Experimental Child Psychology. 75, 152-164.

Oakhlll, 1. V., & Yuill, N. M. (1986). Pronoun resolution in skilled and less skilled comprehenders: Effects of memory load and inferential complexity. Language and Speech. 29, 25-37.

Oakhill, 1. V., & Yuill, N. M. (1988). Understanding of anaphoric relations III skilled and less skilled comprehenders. British Journal of Psychology. 79, 173-186.

Oakhill, 1.V, Cain, K. & Bryant, P. E. (in press). The dissociation of single-word reading and text comprehension: Evidence from component skills. Language and Cognitive Processes.

Oakhill, 1. V., Cain, K. & Yuill, N. (1998). Individual differences in young children's comprehension skill: Toward an integrated model. In C. Hulme and R. M. Joshi (Eds.), Reading and Spelling' Development and Disorders (pp. 343-367). Mahwah, NJ: Lawrence Erlbaum Associates.

Oakhill, 1.V. Hartt, 1. & Samols, D. "Comprehension monitoring and working memory in good and poor comprehenders" Presented at the XIVth Btennial ISSBD Conference, Quebec City, August 12-16 1996.

Oakhill, 1. V., Yuill, N. M .. & Parkin, A. (1986). On the nature of the difference between skilled and lessskilled comprehenders. Journal of Research in Reading, 9, 80-91.

Pany, D., lenkins, 1. R., & Schreck, 1. (1982). Vocabulary instruction: effects of word knowledge and reading comprehension. Learning Disability Quarterly. 5, 202-215.

Pazzaglia, F., Cornoldi, c., & de Bent, R. (1995). Knowledge about reading and self-evaluation in reading disabled children. Advances in Learning and Behavioral Disabilities. 9, 91-117.

Paris, S. G., & lacobs, 1. E. (1984). The benefits of informed instruction for children's reading awareness and comprehension skills. Child Development, 55, 2083-2093.

Paris, S. G., & Myers, M. (1981). Comprehension monitoring, memory and study strategies of good and poor readers. Journal of Reading Behavior, 13, 5-22.

Perfetti, C. A. (1985). Reading Ability. Oxford: Oxford University Press. Perfetti, C. A. (1994). Psycholinguistics and reading ability. In M. A. Gernsbacher (Ed.), Handhook of

Psycho linguistics, (pp. 849-894). San Diego: Academic Press. Perfetti, C. A., Marron, M. A., & Foltz, P. W. (J 996). Sources of comprehension failure: theoretical

perspectives and case studies. In C. Cornoldi & 1. V. Oakhill (Eds.), Reading Comprehension Difficulties Processes and Remediation (pp. 137-165). Mahwah, Nl: Lawrence Erlbaum Associates.

Seigneuric, A., Ehrlich, M.-F., Oakhill, J.V. & Yuill, N.M. (2000). Working memory resources and children's reading comprehension. Reading and Writing. An Interdisciplinary Journal, 13, 81-103.

Semel, E., Wiig, E. H., & Secord., W. (J 987). Clinical Evaluation of Language Fundamentals - Revised. San Diego, CA: The Psychological Corporation.

Shankweiler, D. (1989). How problems of comprehension are related to difficulties in decoding. In D. Shankweiler & I. Y. Liberman (Eds.), Phonology and Reading Disability- Solving the Reading Pu::.:;/e, (pp. 35-68). Ann Arbor: UniverSity of Michigan Press.

Siegel, L. S. & Ryan, E. B. (1989). Development of working memory in normally achieving and subtypes of learntng disabled children. Child Development, 60, 973-80.

Smiley, S. S., Oakley, D. D., Worthen, D., Campione, 1., & Brown, A. L. (1977). Recall of thematically relevant material by adolescent good and poor readers as a function of written versus oral presentation. Journal of Educational Psychology. 69, 381- 387.

Smith, S. T, Macaruso, P., Shankweiler, D., & Crain, S. (1989). Syntactic comprehenSIOn in young poor readers. Applied Psycholinguistics. 10, 429-454.

Spilich, G. J., Vesonder, G. T., Chiesi, H. L., & Voss 1. F. (1979). Text processing of domain-related information for individuals with high and low domain knowledge. Journal of Verbal learning and Verbal Behavior. 18, 275-290.

Stanovich, K. E. (1993). Does reading make you smarter? Literacy and the development of verbal intelligence. In H. Reese (Ed.). Advances in ChIld Development and Behavior, vol. 24. (pp. 133-180). New York: Academic Press.

Stein, N. L., & Glenn, C. G. (1982). Children's concept of time: The development of a story schema. In W. J. Friedman (Ed.), The Developmental Psychology of Time, (pp. 255-282). New York: AcademIC Press.


Sternberg, R. J., & Powell, J. S. (1983). Comprehendmg verbal comprehension. American PsVhologlst, 38, 878-893.

Stothard, S. E., & Hulme, C. (1992). Reading comprehension difficulties in children: The role of language comprehensIOn and working memory skills. Reading and Writmg. An Interdl.\C/plinary Journal, 4. 245-256.

Stothard, S. E., & Hulme, C. (1996). A companson of phonologICal skills m children with readmg comprehension difficulties and children with word reading difficulties. Journal 0/ Child Psvchology and Child Psychiatry, 36~ 399-408.

Taylor, B. M., Frye B. J., & Maruyama, G. M. (1990). Time spent readmg and readmg growth. American EducatIOnal Research Journal. 27, 351-362.

Tunmer, W. E. (1989). The role of language-related factors in readmg disabIlIty. In D. Shankweiler, & I. Y. Liberman (Eds.), Phonology and Reading Disability Solv/Ilg the Readll1g Pu::de. (pp. 91-132). Ann Arbor: University of Michigan Press.

Tunmer, W. E., & Bowey, 1. A. (1984). Metalinguistic awareness and reading acqUIsitIOn. In W. E. Tunmer, C. Pratt, & M. L. Herriman (Eds.), Metalinguisllc AlI'areness 111 Cll/ldren (pp. 144-168). New York: Springer-Verlag.

Wagner, R., & Torgesen, J. K. (1987). The nature of phonological processmg and Its causal role m the acquisition of readmg skills. Psychological Bulletin, 101, 192-212.

Wittrock, M. c., Marks, c., & Doctorow, M. (1975). Readmg as a generative process. Journal of Educational Psychology, 67, 484-489.

Yuill, N., & Joscelyne, T. (1988). Effect of organisational cues and stratcglCs on good and poor comprehenders' story understanding. Journal oj' EducatIOnal Psychology, SO, 152-158

Yuill, N. & Oakhlll, J. (1988). Understanding of anaphorIc relatIOns 1Il skilled and less skilled comprehenders. British Journal of Psychology, 79, 173-186.

Yuill, N. & Oakhlll, J. (1991). Children's Prohlems in Text ComprehenSIOn An E,pemnental Investigation. Cambridge: Cambridge University Press.

YUill, N. M., Oak hill, J. V., & Parkin, A. J. (1989). Workmg memory, comprehensIOn skIll and the resolution of text anomaly. Brillsh Journal of' Psychology, SO, 351-361

Documents

Handbook of Children’s Literacy || Reading Comprehension Difficulties