Evaluation

What is evaluation?

Something you do to test your prototype whether it is working properly. Ask users to test it because they are the one who will use the system in future.

There are 2 types if evaluations:-

1) Formative.
2) Summative.

Formative Evaluation is within the design process evaluation. This provides ways of learning about the design options, user group and analysis of prototypes.

Summative evaluation is a finished system and assesses the quality of the system.

Cognitive Walkthrough:-

An approach to evaluation without users. i.e. formative evaluation. Team members perform this task. User is given a set of relevant questions that are applied to each action. Team goes through each action that the user need to perform on the system. For each and every action, The design is reviewed and problematic features should be noted so that designs can be explored.

Few principles of cognitive design:

1) Automate unwanted workload - Remove mental calculations, estimations, comparisons and any unnecessary thinking to free cognitive resources for high-level tasks.

2) Reduce uncertainty - Display data in a manner that is clear.

3) Fuse data - Bring together lover-level data into a higher-level data to reduce cognitive load.

4) Present new information with meaningful aids to interpretation - Use everyday terms, metaphors, etc.. Use familiar framework.

5) Use names that are conceptually related to function - Names should be context-dependent.

6) Group data in consistently meaningful ways - Within screen, group data logically, across screen group data consistently to reduce search time.

7) Limit data-driven tasks - Reduce the time spent understand raw data by using appropriate colors and graphics.

8) Include in the displays only that information needed by the operator at a given time - Exclude irrelevant information that is not relevant to common tasks so that users can focus on critical data.

9) Provide multiple coding of data - Provide data in multiple formats or levels of detail to satisfy different user preferences.

10) Practice judicious redundancy - To resolve the possible conflict between principles 6 and 8, it is sometimes necessary to include more information than is needed.

Overview of the cognitive walkthrough process:

1- Define inputs to the walkthrough
a) Identification of the users.
b) Sample tasks for evaluation.
c) Action sequences for completing the tasks.
d) Description or implementation of the interface.

2- Organize the analysts

3- Walk through the action sequences for each task
a) Tell a credible story, Considering.........
b) Will the user try to achieve the right effect?
c) Will the user notice that the correct action is available?
d) Will the user associate the correct action with the effect that the user is trying to achieve?
e) If the correct action is performed, will the user see that progress is being made toward a solution of the task?

4- Record critical information
a) User knowledge requirements.
b) Assumptions about the user population.
c) Notes about side issues and design changes.
d) The credible success story.

5- Revise the interface to fix the problems

This is all what i have found about cognitive walkthrough.