eme-2040-design-usability-narr

Design and Usability: 

Design and Usability EME2040: Introduction to Technology for Educators Dr. Richard Hartshorne richard.hartshorne@ucf.edu 407.823.1861

Is good design worth it?: 

Is good design worth it?

Florida Election Ballot (2000): 

Florida Election Ballot (2000)

Three Mile Island (1979): 

Three Mile Island (1979) Incorrect feedback from a faulty pressure release valve showed last action taken, not the actual physical state No direct indicator of coolant in the reactor inferred from other controls Over 100 alarms sounded in seconds, causing panic Water (steam) was escaping the reactor, while incoming water was being reduced This is very bad!

Everyday things???: 

Everyday things???

Norman’s principles of design: 

Norman ’ s principles of design Visibility Mappings Affordances Consistency Constraints Feedback

Visibility: 

Visibility “ what to do ” and “ how to do it ” should be visibly obvious.

Buttons: 

Buttons

Mappings: 

Mappings Relationship between action and outcome helps a user build a good conceptual model users infer from mappings Use physical analogies and cultural standards when using knobs, the standard is: turn right to increase, left to decrease but, when using (light) switches, standards are: U.S.: down = off Britain: down = on Use already established conventions

How do you open the fridge?: 

How do you open the fridge?

Affordances: 

Affordances Visual clue of how to interact with an object knobs afford turning, levers afford moving, buttons afford pushing, etc. Cultural and learned affordances a scrollbar affords scrolling various cursors afford particular operations Well designed objects have good clues Poorly designed objects have no or false clues

Car door handles: 

Car door handles

Kai: 

Kai How do we zoom here?

Good or bad “affordance”?: 

Good or bad “ affordance ” ? How do we zoom here?

Constraints: 

Constraints Physical Constraints constrain possible actions using physical limitations (cannot fit a large key into a small lock) Semantic Constraints constrain possible actions using the meaningfulness of the situation (disable editing controls for a read-only file) Cultural Constraints constrain possible actions using cultural standards (red means error, stop, etc.) Logical Constraints constrain actions based on logical order of the task (Light-rail ticket machine will not accept money until a fare is selected (child/adult/senior, # zones, etc.)

Consistency: 

Consistency Design interfaces to have similar operations and use similar elements for similar tasks For example: always use ctrl key plus first initial of the command for an operation – ctrl+C, ctrl+S, ctrl+O Main benefit is consistent interfaces are easier to learn and use Multiple levels

Internal Consistency: 

Internal Consistency On the same screen Buttons, fonts, etc. From screen to screen UI controls, layout, font family Vocabulary Why? More rapid/accurate pattern induction More confident interaction behavior

External consistency: 

External consistency Refers to consistency across different systems or between real world and a system Mac apps, Windows Apps, WWW Why? Enables transfer of learning from one system to another Visual Metaphors Trash can, etc.

Feedback: 

Feedback Show the outcome of an action obvious: do not hide or make results subtle immediate: effect should be immediate valid: convey the right information persistent: users will forget For error feedback positive tone suggest corrective action use appropriate vocabulary

Error message: 

Error message

The End: 

The End