Heuristic Evaluation
Strategies that can be used are such as..
1) Cancel button ( for dialog waiting for user input ) 2) Quit ( for leaving the program at any time) 3) Defaults to restore property sheet
Task: Entering a Date
1) Text field 2) Three text fields with labels. So one for month, one for year and one for day. 3) 3 Drop down menus. 4) Three text fields with labels plus a default value to show the user how to input their data.
Guidelines
Advice of how to structure the design principles.
Example of a design Principle
An interface should be easy to navigate Provide feedback
Example
Any information should be able to be searched. Focused on user's tasks, not be too large list concrete steps on how to carry out with the problem occuring.
3-5 INSPECTORS
CATCH about 66 to 75% of usability problems. different people find different problems different people might find the same problem
More on it
Give input format . Examples and default values.
Visibility of system status
MUST BE SPECIFIC AS POSSIBLE. BASED ON USER'S INPUT
eXAMPLES"
REFERENCE MANUALS ( very detailed usually used by experts) rarely introduces concepts. table of contents index
Constraint
Reduce the possible actions reduce opportunity for error.
Standards
Specific and measurable rules
Examples:
pop-up, saving bar , cursor shows it is saving with an icon
Design should be
Simply and easily to get use to. If information is complied in the built design and not needed make sure it is greyed out. Display dialogue free
Match between system and real world
System should speak the users language. follow real world conventions, making information appear in a natural and logical order. Present exactly the information the user needs. SPEAK USER'S LANGUAGE/
Speaking the users' language
Terminology based on users' language for task
Control completion examples:
ctrl + c = copy ctrl + v = paste ctrl + z = undo
Problems found will vary according to...
difficulty of the interface being evaluated. the expertise of the inspectors.
Disadvantages :
does not involve real end users dependent on the skill on the evaluator subject to evaluation is bias
Advantage "minimalist approach"
few identified many common usability problems. cheap, cost effective , fast, intuitiveness, and simple to navigate the system .
Developed my MOlich and NIELSEN
heuristic evaluation heuristic inspection guideline-based evaluation discount usability evaluation
Response times
less than 0.1 seconds preceived as "instantenous" one second no interruption 10 seconds user starts to get annoyed. limited time left for user to keep attention on dialog. more than 10 user wants to do other tasks while waiting.
Visibility of system status
should always let the user know that there is an interaction between the system and them. Such that user action = system response in a controlled fashioned and reasonable time.
TAsk vs self-guided
step through the interface using representative end user taks. ensures that specific features of interest are evaluated. but limits the scope of the evaluation - problems may be missed. ensures that problem will be identified in relevant portions of the interface
What are the ten heuristic evaluations ? (Part 1)
1) Visibility of system status 2) Match between system and real world 3) User control and freedom 4) Consistency and standards 5) Error Prevention
Who developed Heuristic Evaluation?
1990, NIELSEN AND MOLICH
Single evaluation catches about
35% of problems.
What are the ten heuristic evaluations ? (Part 1)
6) Recognition rather than recall 7) Flexibility and efficiency of use 8) Aesthetic and minimalist design 9) Help diagonze ,recongize errors and recover from them. 10) Help and documentation
5 evaluators catch
75%
Mapping
Control (widget) - display mapping. Example : TASK : Viewing various parts of the document. Palette controls (widgets) : Only controls that can operate user's selection are fully visible others are greyed out.
Example of Action/Selection Feedback
Cursor re-enforces selection of current button item by becoming the picture of the button item
Design Principles
Design rules that guide the developer's design efforts derived from common design problems in many systems.
Aesthetic and minimalist design
Display dialogues free of irrelevant or rarely needed information. Every extra unit of information in a dialogue competes with the relevant units of information and diminishes their visibility.
Different ways to present this:
Double clicking on a file vs menu select. keyboard and mouse accelerators. command completion. Provide short cuts
Examples of Tasks
Entering a date. Scheduling an appointment.
Why?
Evaluation is not influenced by others AS oppose to being in a team. Greater variability in kinds of errors found no overhead required to organize groups and meetings.
Help and Documentation
Even though it is better when the system can be used without documentation. System should ALWAYS PROVIDE HELP
User Control and Freedom
Example: Supply clearly marked " emergency exit" to the user because users often choose system functions by mistake and will need to leave the unwanted state without having to go and extended dialog or loose data/work.
How does it work?
Inspectors : 3-5 expert in UI and domain of the system. Usually double expert. Or: range of skills in UI, in usability engineer, domain , developer,etc INSPECT INTERFACE ISOLATION EITHER FOLLOW PREDEFINED TASKS OR SELF GUIDED compare notes afterwards WORKS FOR PAPER, PROTOTYPES AND WORKING SYSTEMS.
As an example
Labeling a certain text field as a button above. The user might think that they need to click it. Then that makes it less efficient because those buttons don't do anything.
Recogonition rather than recall
Minimize the user's memory to have to remember. User should not have to remember information from one part of the dialogue to another. Instructions for the system should be visible and or easily accessed. When ever needed.
Examples :
Mondolinks at RGB #----
Help users recognize,diagnose and recover from errors
No code. Precisely indicate the problem as part of the error message. Construct suggest to a solution as part of the error message.
Average problems found..
Novice : 22 regular :41 double specialist : 60
Example:
Old/new versions of software or OS Knowing Word 2003 has transferable skills that may be applied when using Word 2007.
Example of palette controls ( widgets)
On word... selected a picture. Only controls that can operate on a picture are fully visible Others will be greyed out.
Self guide
Open-ended exploration Not necessarily task-directed good for explorating diverse aspects of the interface and to follow potential pitfalls
It works for
PAPER, PROTYPES AND WORKING SYSTEMS
Error Prevention
The system should prevent a problem from occurring. This is better than a good error message. either eliminate error-prone conditions or check for them and present users with a confirmation option before they commit to an action.
Flexibility and efficiency of use
The system should provide accelerators. Ways to speed up the interaction with the expert users. This way both inexperienced and experienced users may be able to use the application fully.
Sceneario 2
They were not used, now we must check when the system is being used, can the usability heuristics be applied in order to increase the usability of the system
Usability Evaluation Scenario 1
Usability heuristics may been followed during design . if so goal of the evaluation is to establish whether the usability requirements have been applied properly.
Long delays
Use: Cursors for short transactions Percent done dialog such as time left and estimated time. Random for unknown times : contacting host . This might take a while.
Example"
User's domain is the part of the real world associated with hte user's work such as BANKING, PUBLISHING, TELECOMMUNICATION,FOOD INDUSTRY, TOURISM.
Transfer effect
Using previous knowledge.
Affordance
Visual affordance : using controls ( example : knobs) from real world -> metaphor.
Consistency and Standards
system should follow platform conventions such that users should not have to wonder whether different words ,situations or actions mean the same thing. BE CONSITENT
Nielsen recommends that...
the interface should always be inspected by individuals
Example of a Guidline
use colour to highlight links feedback should be provided at all stages. greyed out palette control widgets when not needed for an action
