Interface Design

Natural Design

What is natural design?• Intuitive• Considers our learned

behaviors• Naturally designed

products are easy to interpret and understand.

What is unnatural design?• Confusing• Non-intuitive

Natural design in everyday life

• Hot/cold• Push/pull doors

Why do products end up this way (non-intuitive)?

• No user testing• Form over function

Naturally Designed Interactive Media

• What does the underlined text mean?• Where is the menu bar normally placed?• What does a flashing button mean?

Form over function• Look of object is more important than how it

works.– Dolorian?– Women’s shoes?

Limiting the options• A common trait of unnaturally designed

objects is that they have too many options.– E.g. Joseph A. Banks

• Striking a balance between offering a lot of information and not overwhelming the visitor.

What if you can’t limit the options?• www.yahoo.com, www.bbc.com,

www.cnn.com– Enormous amount of information.– Categories presented in heirarchy.– Simple color scheme.– Crucial info above the fold.

Usability• Interactive products that are intuitive and easy

to use have a lot of design effort invested in anticipating, understanding and managing of the users’ expectations.

To aid usability of an interactive experience:

• Remove obstacles. (Let user’s interact with content as directly as possible).

• Minimize effort. (Keep related controls together).• Give feedback. • Be explicit - (What is clickable?)• Be flexible - (Let the user skip features).• Be forgiving - Don’t assume users will do the right

thing.• Take advantage of known conventions.

When can one break the rules?

• Does your target audience have certain knowledge?

• Innovative navigation can help solve access problems. (Interface design would never evolve if nothing new is tried).

• Always test usability.

Usability Testing• Answers the question: Is a technology easy for

the user to utilize?• Executed on all types of products.• Goal: identify and fix as many problems as

possible• Always on software, becoming more popular

on for interactive CDs and web sites.

Who should do the usability test?

• Experts - can comment on problems that violate usability guidelines.

• Users - representative of people who will use product.

Expert reviews of usability• Heuristic Evaluation - checks a web site to see if it violates any rules

contained in a short set of design heurisitics. • Guidelines Review – a much more thorough evaluation that is more

technical – might be able to be automated. One guideline might be checking the use of Alt tags.

• Cognitive Walkthrough – Experts go through a series of tasks the user would perform.

• Consistency Inspection – expert reviews all the web pages on the web site to ensure that the layout, terminology, and color are the same.

• Formal Usability Inspection – designers justify and defend their design choices to expert reviewers, screen by screen.

User Testing• Select representative users – e.g. if the site is for doctors, don’t have

college students participate in your study• How to recruit – pay them or find someone who is enthusiastic about it

and will do it for free.• Select the setting –

– Usability lab – set up with computers and, a camera and recording device, and one- way mirror

– Workplace testing• Bring “lab in a bag”

• Web-based usability testing

User testing - various types• Performance measurement – a quantitative measurement based on a list

of tasks the user is to perform –that the user was able to perform correctly

• Thinking Aloud – users are encourage to verbalize, out loud, their thoughts as they attempt to complete the set of tasks

• Coaching Method – user is assisted by the evaluator, but the user can also ask questions of the product that the evaluator can record.

• Questionaires – not only asking the users to complete the tasks – but then asking them for feedback on what it was like.