Do hypertexts favor comprehension and learning for experts? The effects of prior knowledge diversity Franck Amadieu, André Tricot & Claudette Mariné Work & Cognition Lab. University of Toulouse Extending Cognitive Load Theory and Instructional Design to the Development of Expert Performance August 29 and 30, 2005 Open University of the Netherlands

Schedule of the presentation 1 – Effects of prior knowledge on learning with hypertexts: need to consider knowledge structures 2 – A study about the guidance effects of hypertexts structure and the level of prior knowledge 3 – Purposes for a next study : investigating the consistency of the cognitive structures with the hypertexts structures

Prior knowledge effects in hypertext learning Interaction between hypertext structures (guidance) and level of prior knowledge: –“Experts profit most from a learning system that provides flexible paths, whereas novices seem to benefit more from a learning system that is more structured" (Chen et al., in press). –For experts: higher performance with a low content structure (e.g. Lambiotte & Dansereau, 1992) or no effect of the structure (Müller-Kalthoff & Möller, 2003; Potelle & Rouet, 2003).  lack of a systematic advantage of non-linear structure for experts.

Effect of Knowledge Structure on Learning: Knowledge diversity Effect of the knowledge diversity (abstract schemas effect): –Abstract schemas support inferences, the elaboration of new information and retrieval from memory (Glaser, 1990). –Having only one type of experience may generate beliefs ill- adapted for a new situation (Briggs, 1988), contrary to a diversity of experiences which favours the construction of abstract schemas (Briggs, 1990). –Comparing different cases enhance transfer performance, rather than studying cases separately (Gentner et al, 2003) or studying only one case (Gick & Holyoak, 1983; Paas & van Merriënboer, 1994).

Previous study (exp 1) Domain: studying the cognitive flexibility theory (Participants = teacher-trainees) Factors: structure (linear vs. non-linear = cross links) and level of knowledge diversity of learning theories. Results : – Main positive effect of the knowledge diversity on text- based and situation model questions – Interaction effect between the knowledge diversity and the course structure.

Second study (Exp 2) Domain: infectiousness process of a cell by the HIV (anatomic and functional information) Participants: 55 psychology students (2 nd year) Task: reading and comprehension Factors: –Level of prior knowledge about the cell (pre-test = 10 questions about the cell in general) –Type of guidance: 3 structures of a conceptual map Dependent variables: –Cognitive load –Disorientation –Comprehension: text-based and situation model –On-line data: level of coherence of the learners pathways

Guidances provided by the structures Network: no guidance providedNetwork Linear: guidance for a coherent pathwayLinear –thematic coherence –pre-requisite coherence –temporo-causal sequence of the events was respected Hierarchical: guidance for a coherent pathway + guidance for a representation of the domain structureHierarchical

Cognitive load : 2 subjective measures for 2 distinct results Mental effort invested on learning: main effect of structure Linear < network & hierarchy Perceived complexity of the lesson : interaction effect

Disorientation –For 4 of the 6 items : main effect of the structure showing that network > linear & hierarchy Subjective measures of the learners’ disorientation (6 items : 7-point scales):

Comprehension – spatial information

Main effect of the prior knowledge Comprehension – functional information

Correlationnal analyses For the hierarchical structure : –Correlations between the level of coherence of the paths and the subjective measures: –Correlations between the level of coherence of the paths and the comprehension measures: Level of coherence of the pathway Low knowledgeHigh knowledge mental effort Complexity of the lesson-.69*-.30 Mean disorientation scores-.66*-.29 low knowledgeHigh knowledge Coherence First consultation Coherence Second consultation and + Coherence First consultation Coherence Second consultation and + Text-Based / spatial *.08 Text-Based / functional.07.76* Situation model / spatial *.19 Situation model / functional ** Total scores of text-based.25.77** Total scores of situation model *

Conclusions Disorientation: the network structure entailed more disorientation Mental effort : the linear structure was less demanding. The mental effort may be linked to the hierarchical conceptual maps processing (r(19) =.45* ). The LK learners : –When they followed the coherent path in the hierarchical structure: ↑ performance, ↓ disorientation & perceived complexity. –The LK learners need the semantic representation of the domain combined with a coherent path. The HK learners : –Tended to benefit more from the linear structure = they were able to construct a spatial representation of the domain. –The hierarchical structure seems to interfere with the domain representation of the HK learners.

Next study: knowledge structures The viruses as a domain for the study of the cognitive structures: –Viruses have distinctive infectiousness processes –Some processes are very different whereas others are similar –Some main principles may be abstracted from the different types of infectiousness processes Prior knowledge manipulated: creating cognitive structure from novices participants –The consistency: cognitive structures consistent vs. inconsistent with the new domain structure –The diversity of knowledge: the level of abstraction of the cognitive structures

Assumptions Consistent structure: –Should benefit from an ill-structured hypertext because they have already a suitable structure of the domain. Inconsistent structure: –Should benefit from a well-structured hypertext because their cognitive structure is not fitted to the new domain structure. Abstract schemas: –Should benefit from an ill-structured hypertext. –Should outperform the consistent structure group in the ill- structured hypertext.

Thank you for your attention Contact :

Network structure

Linear structure

Hierarchical structure

Hypertexts for learning Hypertexts requirements: –Discontinuous text processing  jumps (switch) from a topic to another one = the reader has difficulties detecting semantic relationships –The reader has to elaborate his own sequence  learners regulate their learning processes by themselves –Lack of visible bounds of the document  learners have to construct a conceptual structure of the domain to be learned Providing guidance = well-structured hypertexts –Conceptual maps (overall structured representation) provide a representation of the semantic structure of the content. Thus information about the interrelationships between concepts are provided.

Coherence of the pathways Coherence of the pathways: - Main effect of the structure: Network < hierarchical < linear  Thus, hierarchical structure provided well a guidance for a coherent pathway  The navigation behaviours were similar between the Low and Hig prior knowledge learners (si c’est vraiment trop long, je pense que ça pourrait sauter et du coup la suivante aussi: ok, apres un entrainement intensif je vois si besoin est) - Percents of coherent jumps on the total jumps according to the type of structure : Linear = 65,34 %, Hierarchy = 49,72% Network = 10,17 %.

Consultation of the maps according the learning phases

Correlations between disorientation and comprehension Disorientation scores NetworkLinearHierarchical Text-Based / spatial-,61**,11-,41* Text-Based / functional-,48*,04-,51* Situation model / spatial-,48*-,11-,26 Situation model / functional-,57**-,07-,37 Total scores of text-based -,63**,08-,60** Total scores of situation model-,56**-,11-,36 Problem solving task-,52*-12-,28