Is it better to present large amounts of information the same way to all learners, or should the presentation depend on the reader’s level of knowledge about the topic? The results of a study offer important insights about this question for eLearning design.

The study

“Influence of Text Structure and Prior Knowledge of the Learner on Reading Comprehension, Browsing, and Perceived Control.” Calisir, F. and Z. Gurel. Computers in Human Behavior, 19. 2003. (Editor’s Note: Unfortunately, the full text of this article is not readily available online, although at least one site will provide it for a fee.)

The question

How do learners at different levels of expertise engage with differently structured material? Specifically, should we give learners information in a long linear document (e.g., a single-page article) or in a hierarchical format, where they can see the structure and choose links to different parts of the document? Also, is this different for novice learners vs. learners who already have knowledge of the subject?

The method

Participants in this study read a piece of text around 5,000 words long. Of the 30 participants, half were knowledgeable about the subject, having taken a course on it, and half were not. Participants accessed the text on a computer in one of three randomly assigned conditions:

  1. The first group read the text as a linear document, like the kind you might produce in Word.
  2. The second group were given the text as a hierarchically-structured hypertext document: Imagine the Wikipedia page for your favorite TV show, which has several “child” pages, one for each series of the show; each series page in turn has a number of “child” pages, one per episode, etc. In this study, the hierarchical structure went six layers deep.
  3. The last group read the text as a “mixed” hypertext document, similar to the hierarchical group, but with several additional “network-style” links between pages—in the Wikipedia example, extra links like this might connect two episodes starring the same guest actor or connect a series page and an episode page whose titles share a common theme.

So in other words, while the text was the same in all three conditions, participants were able to navigate it in three very different ways.

All participants were given 40 minutes to read the text, during which time the computer tracked the links clicked by those in the hierarchical and mixed groups. A short test was then used to measure participants’ reading comprehension.

The results

First, the unsurprising results: Participants who were knowledgeable about the material performed significantly better in the reading comprehension test than their less knowledgeable peers. This in itself isn’t too surprising, since when you already know something about a topic, it’s much easier to understand and retain new information about it.

Furthermore, there was no significant difference between the test scores of knowledgeable and non-knowledgeable participants across the hierarchical and mixed conditions—this makes sense when you consider that the information in both conditions was hyperlinked with a dominant hierarchical structure, and that participants in both groups clicked about the same number of links while reading.

The really interesting finding was that participants’ level of knowledge about the topic interacted significantly with the different learning conditions to affect how well they scored in the test. Crucially, linearly-presented information appeared to be least suitable for non-knowledgeable participants and most suitable for those who were knowledgeable about the subject. See Figure 1.

Graph showing average reading comprehension scores for knowledgeable and non-knowledgeable participants in the  linear, hierarchical and mixed presentation groups. Linear, Non-knowledgeable: 13.40. Linear, Knowledgeable: 20.80. Hierarchical, Non-knowledgeable: 18.60. Hierarchical, Knowledgeable: 20.20. Mixed, Non-knowledgeable: 17.60. Mixed, Knowledgeable: 17.60.)

Figure 1: Average reading comprehension scores for knowledgeable and non-knowledgeable participants in the linear, hierarchical, and mixed presentation groups

Implications for eLearning design

  1. Consider that long linear documents may be better suited to expert learners. As experts, these learners may already have internalized many of the material’s implicit structural hierarchies—reiterating such structural information might be unnecessarily repetitive, and could result in something like the “expertise reversal effect” (Kalyuga et al).
  2. Help non-expert learners compensate for their lack of mental models of the domain by providing structural information, such as hierarchical relations. Note that a strictly “network-like” hyperlinked environment can disorient beginners (see Mohageg), so it’s a good idea to preserve some recognizable hierarchy.

Additional references:

Kalyuga, S., P. Ayres, P. Chandler, and J. Sweller. “The Expertise Reversal Effect.” Educational Psychologist, 38 (1). 2003.

Mohageg, M. F. “The Influence of Hypertext Linking Structures on the Efficiency of Information Retrieval.” Human Factors, 34. 1992.