Heuristic Evaluation

claims analysis

- a hypothesis about the positive and negative consequences for users and other stakeholders - based on theories, principles, patterns, guidelines or practical experience (using post-it notes)

flexibility and efficiency of use (aka provide shortcuts)

- allow expert users to perform actions more quickly - keyboard shortcuts for menu commands are commonly used

user control and freedom (aka clearly marked exits)

- anything you can screw up, you should be able to un-screw-up - any dialog box you open, you should be able to cancel - any application you open, you should be able to quit - anything that takes a really long time, you should be able to cancel

Usability Inspection Methods

- cognitive walkthrough - claims analysis - heuristic evaluation

types of shortcuts

- commoand abbreviation - frequently used file lists/history - auto-completion - command re-use - good default values **ex: 'pre-order with 1 click (accelerators)**

help users recognize, diagnose and recover from errors (aka provide good error messages)

- error messages should speak the users language - they should be polite - should make it clear exactly what the user was interpreted as doing - should provide insight into how to fix the problem

visibility of system status (aka feedback)

- feedback needs to be rapid, or the user will not think the system 'heard' them - feedback should make it clear exactly what the user was interpreted as doing (and if theres a problem, exactly what the problem was) - ex: typing in a password and its entirely blanked out

recognition rather than recall (aka minimize user memory load)

- people are much better at recognizing something shown to them than recalling things without help - users are very bad at remembering things from screen to screen - its better to allow users to choose from menus

cognitive walkthrough

- provide a list of tasks to evaluators and list of actions needed to complete the task - evaluators step through four questions and verbalize their actions

error prevention (aka prevent errors)

- re-confirmation messages can help, but users can begin to ignore them - ex: do you really want to install this software from spyware.com - you can disable illegal commands or options - you may need to observe what the common errors are in order to prevent them

heuristic evaluation

a 'discount' usability technique -- cheap and quick way to get at major problems (good for early-stage testing) **user-centered but not user-driven**

aesthetic and minimalist design (aka simple and natural dialogue)

every additional piece of information on the screen is: - one more thing to learn how to interpret - one more thing to misunderstand - one more thing to look through when you're looking for something else - one more thing to draw your eye **aim to present exactly the info the user needs (no more, no less)**

performing a heuristic evaluation

go through the interface multiple times (at least twice) - first pass: explore the interface - second pass: identify and record problems

consistency

if the same action accomplishes the same goal in 2 applications or operating systems, then users can transfer their knowledge quickly and easily to the new context - when this is not possible, it slows performance in a new application - even worse, when an application is not internally consistent (the same action accomplishes 2 different effects in some situations); MODES

steps to heuristic evaluation

- small number of evaluators (5 = sweet spot) trained in HE examine and evaluate a UI - each evaluator lists the problems that relate to established usability principles - rate each usability problem according to severity (0 (not a problem) - 4 (catastrophic))

match between system and the real world (aka speak the users language)

- use terms the user will understand, not system-internal or programmer terms - be comprehensible - know your user (expert statisticians may understand 'type III SS' but many users of stats packages might not

Nielson's 10 Usability Heuristics

- visibility of system status - match between system and the real world (speak users language) - user control and freedom (support undo/redo) - consistency and standards - error prevention (make it difficult to make errors) - recognition rather than recall - flexibility and efficiency of use (allow users to tailor frequent actions) - aesthetic and minimalist design (dialogs should not contain info that is irrelevant) - help users recognize, diagnose, and recover from errors (errors in plain language) - help and documentation (provide these)

help and documentation

user don't read manuals, even online ones - they need to be able to access useful help and/or documentation when they need it - help should be **context-sensitive** and **task-oriented** ex: 1 of 300 pages at the top of the screen

consistency and standards (aka be consistent)

users should not have to wonder whether different words, situations, or actions mean the same thing. follow platform conventions