An Example of a Heuristic Evaluation
Reading about heuristic evaluations is only the first step; practicing this technique
will further enhance your skills with it and improve the product you used it on.
To improve your skills, perform a heuristic evaluation on the following Mantel interface. See
how many usability problems you can find. Nielsen and Molich [9] found 29 problems.
Here are some these usability problems along with the heuristics they violated.
Simple and Natural Dialogue
- The function keys should be listed in some logical order, e.g., numerically. The
blank space between PF2 and PF5 should be eliminated.
Speak the User's Language
- From the USERNAME in the example it appears that the system truncates the user's name to
eight characters. In general, computer systems should allow users to enter user and
file names of any reasonable length. Otherwise, the system will either force users
to use unnatural abbreviations or distort the information entered by the user by only
making use of the first N characters.
Minimize User Memory Load
- The telephone number entered by the user should be displayed together with the
subscriber information. The telephone number should appear in a format that is
well-known by the user and accepted as input by the system.
Consistency
- Several different terms are used for the same concept: Number, Telephone No., and
Telephone number.
Feedback
- A response time of 30 seconds to a command from the user is unacceptable. For
technical reasons it may take the system as long as 30 seconds to retrieve the requested
information from external databases. To tell the user what is going on and to show
that the system is active, however, the system should display a message like
"Telephone number (203) 456-7890 is outside the 212 area code so it may take up to 30
seconds to retrieve the information". Every five seconds the system should also
display some indication that it is still working on the command.
Clearly Marked Exits
- When users request information about a telephone number outside the 212 area code, the
system may take up to 30 seconds to answer. The system should provide a facility for
aborting the information retrieval.
Good Error Messages
- The error messages are too vague. The system should inform the user as exactly as
possible about what it knows about the problem - for example, if the area code is missing.
Prevent Errors
- Instead of having error messages for input with parentheses around the area code or with
extra spaces, the system could just accept these common ways of entering telephone
numbers.
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