Usability Heuristics

1. Usability Heuristics • Avoid common design pitfalls by following principles of good design • Nielsen proposes 10 heuristics, others propose more or less. • Inspect an interface for usability problems with these principles

2. Ten Usability Heuristics (from Jakob Nielsen*) • Visibility of system status • The system should always keep users informed about what is going on, through appropriate feedback within reasonable time. • Match between system and the real world • The system should speak the users' language, with words, phrases and concepts familiar to the user, rather than system-oriented terms. Follow real-world conventions, making information appear in a natural and logical order. • User control and freedom • Users often choose system functions by mistake and will need a clearly marked "emergency exit" to leave the unwanted state without having to go through an extended dialogue. Support undo and redo. * http://www.useit.com/papers/heuristic/heuristic_list.html

3. Nielsen’s Usability Heuristics (cont.) • Consistency and standards • Users should not have to wonder whether different words, situations, or actions mean the same thing. Follow platform conventions. • Error prevention • Even better than good error messages is a careful design which prevents a problem from occurring in the first place. • Recognition rather than recall • Make objects, actions, and options visible. The user should not have to remember information from one part of the dialogue to another. Instructions for use of the system should be visible or easily retrievable whenever appropriate. • Flexibility and efficiency of use • Accelerators -- unseen by the novice user -- may often speed up the interaction for the expert user such that the system can cater to both inexperienced and experienced users. Allow users to tailor frequent actions.

4. Nielsen’s Usability Heuristics (cont.) • Aesthetic and minimalist design • Dialogues should not contain information which is irrelevant or rarely needed. Every extra unit of information in a dialogue competes with the relevant units of information and diminishes their relative visibility. • Help users recognize, diagnose, and recover from errors • Error messages should be expressed in plain language (no codes), precisely indicate the problem, and constructively suggest a solution. • Help and documentation • Even though it is better if the system can be used without documentation, it may be necessary to provide help and documentation. Any such information should be easy to search, focused on the user's task, list concrete steps to be carried out, and not be too large.

5. Rating Problem Severity • Severity is based on 3 things • impact • frequency • persistence • Ratings: (modified from Nielsen) 0. Not a problem 1. Cosmetic problem; should be addressed if schedule permits. 2. Grammatical, spelling, or other errors; should be fixed as they can affect users’ impressions of the interface and its creators, but won’t impact usability. 3. Minor problem; should be fixed if possible as this will be an annoyance to users, but won’t affect ability to achieve goals. 4. Major problem; important to fix, as this will impact users’ ability to achieve goals. 5. Catastrophic problem; must be fixed before product is released.

6. Heuristic Evaluation Methodology • Develop a scenario of use • identify typical user, his/her goal(s), expectations, background & experience, knowledge, etc. • define a set of objectives to be achieved • if appropriate, sketch out user’s mental model of how the objective(s) should be achieved (based on previous experience, common practice, etc.) • Access the site under consideration • take the perspective of the user you identified in step 1; attempt to achieve the objectives. • take note of the path, your impressions, potential problems, etc. • ‘Rerun’ the path, taking screen shots of problem pages • paste pages into a Powerpoint file • Annotate the screen shots • circle sources of problems • describe the problem • assign a severity rating

7. An Example • E-commerce web site. • In some cases, the ‘first impression’ a potential customer will get. • For online retailers, the ONLY impression the customer will get! • The following pages represent a portion of the evaluation (full evaluation can take anywhere from several hours to several days, depending on the size and complexity of the site and number of usability problems.)

8. 3 This should let you know what might be recalled. User must go through 3 screens to determine if their product is recalled. 4 1 Blank space (bigger on larger screens) – redesign to resize automatically. 3 Have to scroll down to see the majority of useful information.

9. What do we expect a visitor to want to do? Find out about Whirlpool Corp or find out about products – these should be arranged, separated, etc. 3

10. 4 Too many steps to get to this point – and still several to go before I can purchase the product. No way to learn anything about the retailer – just information about how to prepare for delivery. 4

11. Your Turn … • Go to this web site and choose one link to follow. Perform a heuristic evaluation of the site as it is now. • Spend a few minutes navigating the site. Make notes on your initial impressions, incidents of difficulty or confusion, annoying features, and anything that impresses you about the site. Be sure to note specific pages you wish to return to for the next step. • Select at least 3 pages that have typical or particularly egregious violations of good design that you wish to highlight. • Use the printscreen function to copy and paste each page into a Powerpoint presentation. • Annotate the pages as shown on the previous pages and using the severity ratings given on slide 5. • Send the Powerpoint evaluation to me via email. • Complete the evaluation by Friday, November 14.