Annoy Your Users Less

Session 202Philip Wolfe, Lead Developer

Farm Credit Services of America

What are we talking about?

Human Factors of User Interface Design Human Computer Interaction (HCI) HCI is the study of interaction between people

and computers. (wikipedia) To the user, the user interface IS the system

Creighton University

ITM 734 – Human Factors in Information Systems

The Design of Everyday Things

Donald Norman (1988)

The Humane Interface

Jef Raskin (2000)

We are concerned with Fit

FIT

TASKHUMAN

COMPUTER

Optimize Fit and you optimize performance

Gestalt Psychology

Law of Prägnanz - we tend to order our experience in a manner that is regular, orderly, symmetric, and simple.

Reproductive thinking is solving a problem with previous experiences and what is already known

Your users are trying to make order out of the application that they are using

This may be based on a previously used application

Law of Closure

The mind may experience elements it does not perceive through sensation, in order to complete a regular figure (that is, to increase regularity).

Law of Similarity

The mind groups similar elements into collective entities or totalities. This similarity might depend on relationships of form, color, size, or brightness.

Law of Proximity

Spatial or temporal proximity of elements may induce the mind to perceive a collective or totality.

Law of Symmetry

Symmetrical images are perceived collectively, even in spite of distance.

[ ] [ ] [ ]

Law of Continuity

The mind continues visual, auditory, and kinetic patterns.

A

B

C

D

Law of Common Fate

Elements with the same moving direction are perceived as a collective or unit.

Different Types of Users

Occasional Users Everyday Users Expert Users

Design the interface for each type

Recognition vs. Recall

What is the difference between these two?

What is this an example of?

What is this an example of?

Reduce the cognitive load

Use Models Use Consistency Use the computer's “memory” as much as

possible Don't disrupt the user with

error/warning/information dialogs. They may forget what they were doing.

Donald Norman's Principals

Cognitive Model Visibility Feedback Constraints Affordance Mapping

Cognitive Model

A Mental Model An idea of how something works Physical to more abstract

Structure the interface in a deliberate manner Think of how does the user perceive solving

this task

Visibility

Make all needed options visible Don't distract the user with extra information Don't overwhelm the user with alternatives

Feedback

Communicate to the user about the state of their action

Use more than one method Don't use jargon

Constraints

Limit what the user can perform in certain situations

Affordance

A quality of an object that allows a user to perform an action

Involves the user's goals, plans, values, beliefs, and past experiences

Objects should project how to use them

Mapping

The user has an idea of how the interface is to be used (their mental model)

The object has a conceptional model of how it should be used (the designer's mental model)

When the two meet there is a close mapping. The designer needs to think in a user-centered

way

Jef Raskin's Principles

Monotony of Design – There should be one way of accomplishing a task in a system

Undo – Give users the ability to undo their actions.

Universal use of text – Icon only buttons are cryptic and can be experience / culture specific.

Raskin's Principles cont.

Elimination of warning messages – Users ignore these! Provide a way to undo their action.

Additional Principals

Tolerance – reduce the cost of mistakes by allowing “undo” or expecting varied inputs

Consistency – Users have knowledge of other systems (mental models)

Simplicity – Make common tasks easy, communicate clearly, break down complex tasks

Finalization – Users want to know that their actions were successful or complete

Consistency

What else does this violate?

Finalization

The Uncanny Valley

The more a robot appears to be (look/act) human, the more we notice how it is not human

The Uncanny Valley of Web UI

Is there an uncanny valley for web Uis? The more a web application tries to emulate a

desktop application, the more we focus on the missing pieces.

Summary

Design from the user's perspective Conduct usability studies Remember Norman's Principles Your users are trying to map your system from

something they know Your users are trying to organize your system

into something they can remember

References

Bill Higgins (http://billhiggins.us/weblog/2007/05/17/the-uncanny-valley-of-user-interface-design/) Wikipedia The Design of Everyday Things