Sonja's power point on prior knowlege

The Influence of Prior Knowledge on Expert

Readers’Main Idea Construction

StrategiesPeter P. AfflerbachEmory University

Bibliographic Information

• Afflerbach, Reading Research Quarterly Vol. 25 No.1,(1990). pp. 31-46.

• http://www.jstor.org/stable/747986

Purpose (Goal of Research):

• "Examine systematically the influence of prior knowledge on expert readers' use of strategies to construct a main idea."

Rationale• The researchers wanted to find out answers to these

specific questions:

• "Does prior knowledge of the content domain of text affect the specific strategies used to construct the main idea?"

• "Is the main idea constructed more automatically from a text on a unfamiliar topic?"

• "Are there differences in other reported comprehension processes, such as word identification and assignment of importance, that might mediate the influence of prior knowledge on the main idea?"

• 2 experimental texts• 2 different domains- anthropology and chemistry• 5 paragraph essay• Text A , 596 words;• Text B, 590 words;• Texts rated above graduate level (Level 17 +)• Titles subheadings were removed• Pilot testing with 2nd group indicated that explicit main

idea statements were not in texts• 3 practice texts were used to help students learn how to do

a think aloud

Methodology

Participants and Demographics

• Four anthropology students• Four chemistry students• The students were all doctoral candidates and

knowledgeable in their fields• The students were not familiar with the literature of text

processing, reading comprehension, or cognitive psychology

• Screened to eliminate biases

Time Frame

• 1 week required of participants to reflect on strategies used when reading

• Time it took to conduct experiment was estimated to be a day- but not explicitly stated in the journal

Methods for Collecting Data

• Visual prompts (red markers) at end of sentence (gave verbal report)

• Prompts were put in at the end of each paragraph (gave the main idea)

• Prompts put at the end of selection (gave the main idea of the selection)

Data

Data

Data

Data

Data

Findings

• Total number of strategy reports for 8 subjects was 96• Based on the 3 strategies used• Studies found no substantial difference between students

in area of anthropology and chemistry• Main Conclusion: Readers that don't have enough

background knowledge for a text topic the "difficulty of main idea construction is compounded."

Limitations of Study

• Verbal report• "… make it difficult to determine whether automatic main

idea construction is a unique process, an automated version of a construction strategy (such as draft and revision), or simply affirmation of a main idea which the reader with high prior knowledge brings to the reading task." (p.43)

• "Structural analysis of the texts was not performed." What this means is that the "possible effects of text structure on the main idea construction strategies were not measured."

Implications for Teaching

• Need to be cautious when teaching main idea• Expert Readers have difficulty• Need Prior Knowledge