WebWeb--Sites Evaluation Sites Evaluation Through EyeThrough Eye--Movements Movements

InvestigationInvestigation

Francesco MaringelliSensoMotoric Instruments GmbH – Teltow/Berlin (Germany)

International School for Advanced Studies, Cognitive Neuroscience Sector – Trieste (Italy)

GIMO2000 GIMO2000 -- PaviaPavia

Web Web -- Sites Evaluation Through EyeSites Evaluation Through Eye--Movements InvestigationMovements Investigation

To write for the web is different than to write for other types of media. Following, we will analyze differences between:

Print – WebTV – WebGUI - Web

WebWeb--Design and Evaluation:Design and Evaluation:BackgroundBackground

Web Web -- Sites Evaluation Through EyeSites Evaluation Through Eye--Movements InvestigationMovements Investigation

Print - Web• Speed (very fast/quite

slow)• Dimensionality (2-D/N-D)• Navigation

(limited/unlimited)• Canvas size (large/small)• Image quality (High/low)• Multimedia (low/high)• Interactivity (low/high)

Web Web -- Sites Evaluation Through EyeSites Evaluation Through Eye--Movements InvestigationMovements Investigation

TV – Web• Screen Resolution

(relatively poor/potentially reach)

• Input information (low/high)

• Viewing distance (far/close)• User posture

(relaxed/upright)• Nr. of users at the same

site/time (social/solitary)• User engagement

(passive/active)

Web Web -- Sites Evaluation Through EyeSites Evaluation Through Eye--Movements InvestigationMovements Investigation

GUI - Web• Control over actual

layout (high/low)• Difference in display

area (factor of 6/ factor of 100)

• Navigation control (high/low)

• “Integration” (single/multiple and part/whole)

Web Web -- Sites Evaluation Through EyeSites Evaluation Through Eye--Movements InvestigationMovements Investigation

Currently, there are a number of different approaches to Web design evaluation.

It is possible to assign them to two large and broadly different classes:

Subjective Evaluation (self-report, expert evaluation, role-playing, …)

Objective Evaluation (video-tapes, mouse rec., eye-movement rec., …)

WebWeb--Design and Evaluation:Design and Evaluation:State of the ArtState of the Art

Web Web -- Sites Evaluation Through EyeSites Evaluation Through Eye--Movements InvestigationMovements Investigation

• Expert Evaluation (knowledge-based review by usability expert);

• Informal Developer Walkthrough(unstructured review by developers);

• Heuristic Evaluation (Nielsen and Norman, unstructured review of interface design done by trained evaluators);

Subjective MethodsSubjective Methods

Web Web -- Sites Evaluation Through EyeSites Evaluation Through Eye--Movements InvestigationMovements Investigation

• Cognitive Walkthrough (Lewis and Polson, structured group walkthrough of design, post-hoc analysis based on cognitive theories)

• Pluralistic Usability Walkthrough (Bias, users, developers, and experts walkthrough in user role, action recording, discussion)

• Joint Design Walkthrough (Also called “paper prototype testing”, Developers and users evaluation group)

• Collaborative Usability Inspection (Costantineand Lockwood, Structured review of web-siteusability)

Web Web -- Sites Evaluation Through EyeSites Evaluation Through Eye--Movements InvestigationMovements Investigation

• Mouse-click recording and analysis(dedicated software able to keep track of mouse movements and mouse selections)

• Video-tapes recording and analysis(simple recording of users behavior, to be analyzed through video play-back)

• Eye-tracking recording and analysis (eye-movements recording, then analysis)

Objective MethodsObjective Methods

Web Web -- Sites Evaluation Through EyeSites Evaluation Through Eye--Movements InvestigationMovements Investigation

• There are a few available examples of Web-design evaluation through eye-tracking research, although there is a growing interest in this approach.

• The main advantage of such a technique is the possibility to map out how Web surfers really interact with a site, greatly limiting biases and errors due to both self-reports and observation approaches.

WebWeb--Design Evaluation Through EyeDesign Evaluation Through Eye--Movements AnalysisMovements Analysis

Web Web -- Sites Evaluation Through EyeSites Evaluation Through Eye--Movements InvestigationMovements Investigation

• The Stanford-Poynter study was the first investigation trying to document which way 67 recruited volunteers read on-line newspaper.

• Results from this study, according to the Authors, are not congruent with current web-design guidelines.

Web Web -- Sites Evaluation Through EyeSites Evaluation Through Eye--Movements InvestigationMovements Investigation

Results

• Text seemed more attracting than photos or graphics.

• Banner advertisements do catch readers’ attention.

• Graphics other than banners were looked about 22 % of the time.

• Online news readers read shallow but wide, while at the same time pursuing selected topics in depth.

Web Web -- Sites Evaluation Through EyeSites Evaluation Through Eye--Movements InvestigationMovements Investigation

Reading behaviorCognitive workloadLevel of attention

Viewers entry pointLevel of frustration

Authors concluded that Eye-Movements analysis gave them highly relevant data,

otherwise not collectable, such us:

Web Web -- Sites Evaluation Through EyeSites Evaluation Through Eye--Movements InvestigationMovements Investigation

• Nowadays, only descriptive studies are available.

• Lack of a theoretical model within which to interpret the data and be able to make predictions.

• Eye-trackers are not currently supported by any internet browser – off-line, manual analysis of data is required.

Current Limitation of Web-Evaluation through Eye-Movements Analysis