Memory & Cognition1973, Vol. 1, No.3, 297·300

Encoding differences in recognition and recall*STEPHEN T. CAREYt and ROBERT S. LOCKHART

University of Toronto, TorontoM5S 1A1, Ontario, Canada

After practice consisting of the free recall of five blocked categorized lists, Ss were presented a sixth list and thenunexpectedly tested for recognition. After practice at recognition of the same five lists, Ss were unexpectedly tested forrecall following presentation of the sixth test. Recognition performance was superior when items were encoded inanticipation of a recognition test. Intracategory serial position functions for Ss anticipating recall tests were differentfrom those anticipating recognition tests regardless of the retention test employed. The role of control processes inrecall and recognition testing is discussed.

Much research has been directed at isolatingdifferences between recall and recognition processes.Two-process theories (e.g., Kintsch, 1968, 1970)propose that organization has little or no effect uponrecognition, since organization facilitates retrieval andretrieval in recognition is assumed to be trivial.Single-process (threshold) theories of recognition andrecall (e.g., Postman, Jenkins, & Postman, 1948)maintain that recognition and recall provide alternativemeasures of associate strength and that, if organizationfacilitates recall, it should facilitate recognition.Evidence that organization does facilitate recognitionperformance (e.g., Mandler & Borges, 1971; Mandler,1972) is often used to support the single-processviewpoint, or the conclusion that recognition involves aretrieval component that is nontrivial.

A neglected question is whether typicalrecall-recognition comparisons confound storagedifferences with retrieval differences. Such storageeffects could result from control processes which differdepending on whether the S is anticipating a recall orrecognition test. For convenience, we will refer to thesecontrol processes, respectively, as recall and recognition"modes of processing" and ask the question of whetherthese modes differ in any important respect. Insofar assuch differences exist, they would constitute asignificant factor in any comparison between recognitionand recall performance.

Free recall was used in the present investigation, sinceorganization has been widely studied in this paradigm.Furthermore, Ss were given practice at either recognitionor recall modes of storage on the premise that if thereare different control processes for these tasks, naive Ssmust be given the opportunity to develop them. It isassumed that such practice is sufficient for thedevelopment of a storage mode optimal for theparticular test of retention.

*This research was supported by aN ational Research Councilof Canada Award to the first author and by ResearchGrant 0355 from the Research Council of Canada to the secondauthor.

[Requests for reprints should be sent to Stephen T. Carey,Department of Psychology, University of Alberta, Edmonton,Alberta, Canada.

In order to assess differences between recognition andrecall storage modes, Ss who were given practice withone form of retention test (recognition or free recall)were unexpectedly tested, following final listpresentation, by the alternate form of test. Therefore, Ssin the recall mode of storage condition free recalled fivedifferent single-trial lists with blocked categories, and Ssin the recognition mode of storage were tested forrecognition after each of the same five lists. Followingpresentation of the sixth list, Ss who had practiced inthe recall mode of storage and testing were tested forrecognition, while those who had practiced in therecognition mode of storage were tested for free recall.A comparison of recall performance between Trial 5 andTrial 6 was used as an estimate of the difference betweenrecall and recognition storage processes as measured byrecall. A comparison between Trial 5 and Trial 6recognition performance scores estimates thecorresponding difference between storage effects whentested by recognition.

Theories which propose that learning depends onorganization make different predictions concerning theeffect of organization on recognition performance,depending upon whether they are combined withone-process or two-process theories of recall andrecognition. If threshold theory is invoked, thenstudying material in anticipation of recall (as opposed torecognition) can prove only beneficial, whetherretention is tested by recognition or recall, since recallinstructions increase organization and organizationfacilitates learning. If the two-process theory of recall isespoused, then storing material under recall taskdemands should facilitate recall since organizationfacilitates retrieval. It should not influence recognition,however, because recognition does not involve retrieval.On the other hand, theories which assert the priority ofcontrol processes (e.g., Atkinson & Shiffrin, 1968;Norman & Rumelhart, 1970) do not make suchpredictions. Rather, these theories emphasize that whatis stored is a function of the task demands. Thus,optimal performance may occur when S activates theappropriate control processes for a given task. Thisviewpoint would predict maximal performance when themethod of test used is that anticipated by S. However,

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these latter predictions have not been supported byprevious investigations. First, Freund, Brelsford, andAtkinson (1969) found no difference betweenrecognition performance on material that was stored inanticipation of recall testing and material stored inanticipation of recognition testing in a paired-associateparadigm. Second, Loftus (1971), using a continuouspaired-associate paradigm, found that recognitionperformance was superior when material was storedunder conditions of uncertainty of test (mixed mode)than when it was stored in anticipation of a recognitiontest.

The rationale for usingblocked categorized lists in thepresent study was to predispose S to a type oforganization processing which was capable of beinganalyzed in spite of single-trial presentation. If, indeed,there are differences between recall and recognitionmodes of processing, it was hypothesized that thesedifferences might be observable from a comparison ofintracategory serial position functions for blockedcategorized lists. For example, during recognitionprocessing, attempts to discriminate targets fromsemantically similar lures might seem an effective formof encoding. During recall processing, organization andunitization might benefit more from encoding commonattributes among the items. While there is some evidencethat intracategory serial position functions for recallmode of storage show probability of recall to varyinversely with intracategory serial position (Wood &Underwood, 1967), these functions have not beeninvestigated for the recognition mode of processing. Ifthe recognition mode of processing largely involvesdiscrimination learning rather than unitization, thenthese intracategory serial position functions may beexpected to be lesssteep than those for recall processing.

METHOD

Subjects

The Ss were 66 introductory psychology students from theUniversity of Toronto.

Materials

Stimulus materials consisted of 48 categories of 10 items each,taken from the Battig and Montague (1%9) norms. Twelve listsof 40 items were constructed, each list consisting of 8 categoriesof five exemplars. This permitted 6 lists to be presented to eachS, with a parallel set of 6 lists, equated for category membership,to be used for lures in the two-alternative forced-choicerecognition test (2 AFC). The exemplars from each of thecommon categories for each of the six pairs of lists werebalanced for mean frequency of occurrence. Thus, each set of 6lists could be interchangeably used for a target set or a distractorset. Each of the 12 blocked categorized lists was randomized 10times for both category and intracategory sequences. Inaddition, 10 different randomizations were used of the order inwhich the 6 lists were presented.

Procedure

Blocked categorized free recall lists were presented at a l-sec

rate by means of a closed-circuit TV camera focused on aone-word aperture of a selectric typewriter carriage bearingcomputer-printed lists. A diapilot, reading signals on magnetictape, activated a solenoid which advanced the carriage with achange time of 100 msec. In an adjacent room, Ss in groups,ranging in size from two to four, viewed the presented materialon individual TV monitors, separated by soundboard partitions.For each of the first five lists, following list presentation, Ss inall conditions engaged in the multiplication of three-digitnumbers exposed on their TV monitors for I min. This task wasused to eliminate recency effects (Glanzer & Cunitz , 1966).Then Ss were given either a 2-min recognition test or wereallowed 2 min for free recall. On the sixth trial, Ss who had beenpracticed in recall were instructed, following list presentationand 30 sec of multiplication, to perform a 2 AFC recognitiontest for the list that they had just seen. In all recognition tests, Sswere informed that one of each of the 40 word pairs were fromthe previous list and that the other word of the pair had notbeen seen previously in this experiment. They were given 3 secto indicate whether the "old" item was the left or right memberof each pair.

For the recognition storage condition, following each of thefirst five list presentations and 1 min of multiplication, Ss weretested by the 2 AFC recognition test. Following the sixth-listpresentation and 30 sec of multiplication, these Ss were told tofree recall the most recent list.

RESULTS

An analysis of variance of the first five lists found thatfor the recognition data there is a slight increase inperformance across successive lists amounting to anaverage increment in probability correct of 0.01. Despiteits negligible magnitude, this effect is significant[F(4,800) = 2.4, p < .05]. Similarly, there is a smalldecrement in performance across successive free recalllists averaging 0.02 in the probability of correct recall.Although the magnitude of this effect is again negligible,it does reach statistical significance [F(4,800) = 7.5,P< .01] . Considering the high degree of precision in thepresent experiment, such statistical significance is notimpressive, and these effects will be considered to havelittle substantive importance.

In the analysis of the first five lists, both recognitionand recall data showed reliable intracategory serialposition effects [F(4,800) = 5.0, P < .01 and F(4,800) =16.2, P< .01, respectively, as graphed in Fig. 1]. Therewas no intracategory Serial Position by List interaction[F(l6,800) = 1.1 and F(l6,800) = 1.0 fur recognitionand recall, respectively] . Inspection of Fig. 1 also revealsthat the intracategory serial position function appearsmuch steeper across serial positions for the recallcondition than for the recognition condition.

Figure 2 depicts the probability of recognition acrossintracategory serial positions for List 5 and List 6collapsed over categories. The comparison is madebetween List 5 and List 6 in order that a contrast inperformance on a common recognition test can be seenbetween Ss practiced in either recognition or recall formof encoding. Thus, the difference between the twofunctions represents a storage difference betweenrecognition processing (List 5) and recall processing

ENCODING DIFFERENCES IN RECOGNITION AND RECALL 299

(List 6) as measured by recognition testing. Analysis ofvariance of this recognition data showed List 5 to besuperior to List 6 [F(1,64) = 14.6, p < .01], theintracategory serial position effect to be significant[F(4,256) = 3.7, p < .01], and the intracategory SerialPosition by List interaction to be significant [F(4,256) =4.9, P < .01]. This means that if retention is tested byrecognition, performance will be better if the material isprocessed in anticipation of a recognition test asopposed to a recall test. In addition, the inferiority ofthe recall mode of processing increases withintracategory serial position when retention is tested byrecognition.

Figure 3 represents the probability of recall of itemsas a function of intracategory serial position collapsedover categories for List 6 (stored in anticipation of arecognition test) and List 5 (stored in anticipation of arecall test) for practiced Ss. Again, the comparison ofperformance is made between List 5 and List 6 in orderthat Ss who were practiced in two different forms ofencoding could be tested on a common recall test.Differences between these two functions then representstorage differences between recognition and recall modesof storage when tested by free recall. Analysis ofvariance of these recall data yielded no main effect[F(1,64) < 1] , a significant intracategory serial positioneffect [F(4,256) = 4.0, P< .01], and a significantin t racategory Serial Position by Storage Modeinteraction [F(4,256) = 4.2, p < .01]. These resultsmean that under expectations of a recall test, S processesthe material in such a manner that difficulty ofsubsequent retrieval varies with intracategory serialposition. On the other hand, no such serial positioneffects appear for material stored in anticipation of a

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recognition test but tested by free recall. Interpretationof the lack of a main effect for mode of processing whenretention is tested by free recall must allow for thepossibility that Ss practiced in recognition mode andaware of the categorized nature of the list transformedthe recall test into a recognition test by retaining thecategory labels. Although organizational activity led tono overall advantage in recall when compared withrecognition processing, the difference in storage betweenthe two modes of processing is evident from theinteraction between the intracategory serial positionfunction and mode of processing.

Taken together, Fig. 2 and Fig. 3 argue that theanticipated form of test results in differential storage ofinformation and this difference in storage variessignificantly with intracategory serial position regardlessof the form of test by which it is measured.

1DISCUSSION

This study demonstrates several findings which mayhave important implications for theories of recall andrecognition performance. First, the data suggest thatorganization activities do not invariably lead to superiorrecognition performance; in this study organizingmaterial in anticipation of a free recall test led toinferior recognition performance.

Second, the data suggest that the differencesbetweenrecall and recognition performance for practiced Ss maybe in part attributable to differences in encoding andstorage and not solely attributable to retrievaldifferences as is often claimed (e.g., Freund, Brelsford,&Atkinson, 1969). Clearly, the differences between

300 CAREY ANDLOCKHART

recognition and recall performance (McCormack, 1972).If this is so. it follows that a lack of a difference inrecognition performance between sets of stimulusmaterial that differ in ease of organization cannotnecessarily be used to argue for the two-stage theory ofrecall and recognition (e.g., Kintsch, 1970). In a similarmanner, the present study raises the possibility that adifference in recognition performance between sets ofstimulus material that are subjected to different amountsof organizational activities cannot necessarily beaccepted as unqualified evidence for the necessity of aretrieval step in recognition. Finally, it is proposed thatan analysis of intracategory serial position functions(Murdock & Carey, 1972) may be a more sensitive indexof differences in processing modes than is overallprobability of retention.

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intracategory serial position functions for recall andrecognition modes of encoding are suggestive evidencefor differential storage between these two modes ofprocessing. This finding is reinforced by the fact thatencoding and storage differences between recall andrecognition processing modes reliably appeared whetherretention was tested by recognition or recallwithin eachprocessing mode. This means that the manner in which apracticed S encodes a given item will depend in part onthe anticipated form of test. More generally, this isconsistent with the viewpoint that Ss encode and storeverbal material in a format that they believe will permitoptimal utilization.

Previous attempts to isolate storage differencesbetween recall and recognition modes of processing mayhave failed due to the minimal role that organizationalprocesses would play in studies which employedpaired-associate tasks with single letters and digits asstimuli and responses (e.g., Freund, Brelsford, &Atkinson, 1969) and/or due to the limited practice Sswere given at developing processing modes which wereoptimal to the specific task demands (e.g., Loftus,1971). The present study emphasizes the possibility thatutilization of stored information should be maximalwhen knowledge of the functional properties of retrievalis available to Ss at time of encoding. These resultsemphasize, therefore, the need to control for possiblestorage effects when evidence (e.g., Mandler, 1972;Kintsch, 1968, 1970) of the influence of organization onrecognition performance is discussed. Different controlprocesses for recognition and recall processing may beone more obstacle to the direct comparison of

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(Received for publication December 27,1972:revision received February 28. 1973.)