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Interface Analysis

Heuristic evaluation

Heuristic Analysis of ETW
The following is a heuristic analysis of the ETW system using the following heuristics (borrowed from 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.
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.
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.


(severities range from 0 (not a problem) to 4 (redesign needed) )
Heuristic Identified: Visibility of System Status
Reason: There is no light on the display to identify it as being on. When the device is on, in some conditions the display is so difficult to see that it cannot be ascertained whether the device is on at all.
Severity: 1

Heuristic Identified: Visibility of System Status
Reason: When entering numbers the PCO must look at the display to see which number was entered. The keys are too close together when using gloves, and verifying this requires visually scanning the display (sometimes at great difficulty) for the appropriate feedback.
Severity: 3

Heuristic Identified: Match Between System and the Real World
Reason: The page up and page down keys are located horizontally adjacent to each other in the middle of the keypad.
Severity: 1

Heuristic Identified: Error Prevention
Reason: Keys are too close to other and too small. Wearing gloves in cold weather could cause multiple keys to be pressed.
Severity: 2

Heuristic Identified: Recognition Rather Than Recall
Reason: Several instances require recall from the PCO: entering zone location, entering violation code, and even entering parking tag number (due to the length of the parking tag number).
Severity: 4

Heuristic Identified: Recognition Rather Than Recall
Reason: It is difficult to ascertain the current step in the task. There is no way of knowing how far in the pipeline the user is, nor how many steps are left.
Severity: 3


Main menu
A Enter new citation
B Browse/Void citations
C Browse master files
D Property maintenance
E Chalk Tires - if in a service vehicle area. allowed 30 minutes.
F Keyboard Help
G Utilization - count lots
H secure unit
I exit to dos
L more options...

More Options
A Test Printer
B Set Date/time
D Maintain control File
E Maintain license info
G Motor Assistance form - jumpstart lockout
H Communications - clear it for the day, put it in download mode
J Utilities - lights on, contrast
L More options

Heuristic Checklist for Controls

Physical Characteristics:

1. Is the size of the control appropriate
  • a. For the user?
  • b. For the environment?
  • c. For the task?
2. Is the contrast of the control
  • a. Perceivable by the user?
  • b. Perceivable in the environment?
  • c. Appropriate for the task?
3. Is the placement of the control
  • a. Perceivable by the user?
  • b. Perceivable in the environment?
  • c. Appropriate for the task?
4. Can the control be physically manipulated
  • a. Correctly by the user?
  • b. Properly in the environment?
  • c. Appropriately for the task?

Universal Usability Characteristics:

1. Is the control visible and accessible to users regardless of
  • a. Physical/Cognitive abilities?
  • b. Task environment?
2. Is the visibility of the control
  • a. Multi-modal?
  • b. Redundant?

Cognitive/Performance Characteristics:

1. Is the feedback of the control
  • a. Timely?
  • b. Perceivable by the user?
  • c. Perceivable in the environment?
  • d. Understandable by the user?
  • e. Appropriate for the task?
  • f. Redundant?
  • g. Multi-Modal?
2. Does the control have
  • a. Conceptual compatibility?
  • b. Movement compatibility?
  • c. Spatial compatibility?
  • d. Modality compatibility?
3. Does the control guard against accidental activation
  • a. By the user?
  • b. By the environment?
  • c. By the task? (e.g. performing one function accidentally starts another function)
4. Is the intentional activation
  • a. Require the appropriate amount of force by the user?
  • b. Require the appropriate number of steps?
  • c. Easily findable?
5. Is the mobility of the control appropriate for
  • a. The user?
  • b. The environment?
  • c. The task?
6. Are the aesthetics of the control appropriate for
  • a. The user?
  • b. The environment?
  • c. The task?



1A: it's ok
1B: when it's cold, gloves make fingers too big.
1C: Yes

2A: Not at all times
2B: No
2C: No

3A: 1-7, gets a 3
3B: N/A
3C: Yes

4A: yes
4B: no (cold)
4C: no

Universal Usability Characteristics:

1A: No
1B: No

2A: No
2B: No

Cognitive/Performance Characteristics

1A: Yes
1B: Yes
1C: No
1D: Yes
1E: No
1F: Somewhat
1G: Yes

2A: No, Shift-F Shift-G Page/up/down
2B: N/A or No
2C: No (display abcdefg down, handheld across. page up/down)
2D: No (textual/verbal)

3A: No No keylock. crappy buttons
3B: No - lay something on it it will push buttons
3C: No, controls so close, mean to press one button accidentally hit another

4A: weak yes/no
4B: no
4C: yes

5A: yes
5B: yes
5C: yes

6A: yes
6B: yes
6C: yes

Last modified 21 November 2004 at 11:08 pm by Jaroslav Tyman