Before usability

CS 147: Intro to HCIDan Maynes-Aminzade

After 1st Usability Review

After 2nd Usability Review

After Usability

After feedback from Don Norman(which cost me $25,000)

Plans for Today

• Assignment 2 discussion in small groups

• Group discussion of lessons learned from Assignment 2

• Quick summary of project proposals + discussion

• Terminology recap

• Form groups for projects

Terminology of InteractiveSystem Design

• Affordances

• Constraints

• Conceptual Models

• Mappings

• Visibility

• Feedback

Affordances

• Attribute of an object that allows people to know how to use it

Constraints

• Restricting interaction to reduce errors

Conceptual Model

• A set of ideas about how an interactive system behaves

vs.

Mapping

• Relationship between controls and their effects on the world

Visibility

• Making it obvious which actions are available

Feedback

• Send information about what is happening back to the user

Usability Breakdown

• My action causes something I did not expect or want

• I want to do something, and cannot figure out how

Assignment 1 Grading Criteria

• Good– Chose an appropriate interactive interface, and

described its problems in terms of the principles in the readings

– Characterized the breakdown as described in the assignment: what was tried, what was expected, what happened

– Described the issue in specific terms, using terminology and principles from the readings

– Suggested an alternative design that solved the problem and described how it was better grounded in the general principles

Assignment 1 Grading Criteria

• Bad– Chose a technology problem rather than a design

problem (e.g. “system crashed” or “device was broken”)

– Copied one of the examples from the reading– Explained in vague terms (e.g. “design was bad”)– Didn’t offer an alternative design– Didn’t show evidence of doing the reading (didn’t use

the appropriate principles, or applied them incorrectly)