Abstract:

Expository texts are mainly characterized by presenting abstract categories and embodying abundant inter-related concepts and relational information. The design of expository texts is in a way to prescribe a fixed processing route. However, it becomes difficult for a reader to encode multiple concept relations simultaneously, which, consequently, according to cognitive load theory, imposes heavy cognitive demands on working memory. Causal diagrams as a form of external adjunct aids have been largely examined in recent years as a potential breakthrough in easing out the problems associated with comprehending expository texts. The main purpose of the current study was to examine whether the effect of causal diagrams on expository texts reading could be different to individuals with different cognitive styles. Three experiments were designed to examine the effect of causal diagrams on expository text for different cognitive style individuals. ExperimentⅠexamined whether causal diagram could facilitate expository texts reading for individuals with different cognitive styles by comparing their reading under the condition of a text with or without a causal diagram. ExperimentⅡexamined the difference of process effort and performance for individuals with different cognitive styles by comparing their reading under the condition of causal diagram + text and text + text. Using think-aloud protocols, Experiment Ⅲ examined the influence of causal diagram on readers’ comprehension strategy for individuals with different cognitive styles by comparing their reading under the condition of a text with or without a causal diagram. The results were that, compared to a single text, field independent (FI) individuals’ reading scores were improved while the reading time was not increased when presented with a text with a causal diagram; furthermore, more causal-bridging inferences and questioning strategies were generated. However, field dependent (FD) individuals’ reading scores and reading time were significantly improved, while their comprehension strategies were not changed when presented with a text with a causal diagram. The results revealed that causal diagram could improve reading performance of the expository text for both FI and FD. FI individuals didn’t increase more processing effort when presented with a causal diagram, and they improved their reading efficiency by adjusting the comprehension strategies, while FD individuals improved their reading efficiency by increasing more processing effort, and their comprehension strategies were not changed.

Key words: adjunct aids, causal diagram, expository texts, cognitive style