Overview of Navigation Readings Matt Koehler CEP 909 Nov 14, 2001

Nielson The problem of being “lost in hyperspace” Strategies for avoiding it –Guided Tours –Easy to “Backtrack” –History Lists –Bookmarks –Overview Diagrams (many forms - avoid spaghetti) –Use of Metaphors

Dee-Lucas: Study Overview Contrast: Overview is a listing vs. Overview is hierarchically organized vs. No overview (traditional text). Students read all text, then left to review with the listing or hierarchical organization Subjects Completed: Summary of main points, free- recall of all content, recall of unit names, useability evaluation. Experiment 1: Vague learning goal (study for some unspecified test Experiment 2: Goal was to write a summary Experiment 3: More vs. Less segmented hypertext

Dee-Lucas: Study Findings Useability: Hierarchical reported as easier to use than simple listing Recall of Unit Titles: Groups with an overview much better at recall titles (no diff linear vs. hierarchical) Locations: Hierarchical group was better able to locate the information in the hypertext Review Strategies: Less subjects reviewed material in linearly structured overviews in Exp #1, but not Exp #2. List overviews lead to LONGER time spent reviewing.

Dee-Lucas: Study Findings Free Recall: No differences Summary Writing: linearly structured overviews led to less ideas in the review More segmented hypertext: Longer times to select something to read, Able to recall more titles (but there are more titles), less able to recall common titles, better able to recall location of information, less likely to review irrelevant information Recalling and Reviewing in more segmented hypertext: No difference on number of ideas recalled, but more likely to recall details and less big ideas.

Dee-Lucas: Summary Structure (hierarchal): Better recall, more efficient use of software. Might be bad that students don’t encounter “off-task” information. Less structure: Might be better for extremely motivated learners with a particular learning goal.

Ford and Chen: Overview Seek to relate learning styles with what subjects do with what they learn Cognitive styles: –Field Dependence: the degree to which a person’s perception of information is affected by the surrounding perceptual contextual field. (Embedded Figures Test.). These people require more external structure and instructions. –Field Independent: Provide their own structure, think outside the box, etc. –Holists vs. Serialists

Ford and Chen: Results Field Dependent People: Make greater use of the map, less use of the index, less use of back/fwd buttons, spend time on higher-order ideas, less time on details, no learning differences Learning was predicted by: Past experience (web page use and internet use -- should have picked a different task). Experience predicts: more pages viewed, more details being explored, less time learning, less practice. BIG PICTURE: Style (field dependence) predicts strategy, other things like experience predict how much is learned.

Lawless: Summary Seeks to characterize the patterns of hypermedia use: –Apathetic users (don’t do much or learn much) –Knowledge seekers (explore links to learn things, spend time on screens) –Feature explorers (want to try a little bit of every tool in the system). Attempts to relate prior knowledge and interest to these patterns

Lawless: Summary Feature explorers - seem to be low-prior knowledge people who get sucked in by the bells and whistles Apathetic users - Either already high knowledge people or low interest people Knowledge seekers - People with moderate amounts of prior knowledge

Big Big Picture The big question: Is hypermedia better than linear text? The answer: it depends. –On users –On the text –On what tools are provided Be careful to avoid getting people “lost in hyperspace” The structure of the information matters -- it affects what people learn and how they use the system. How people use the system is probably influenced by a lot of things –Prior Knowledge –Learning Style –Individual differences (age, sex, income, etc) Better make systems that allow different uses of the system so that these differences can be accommodated