Many Factors Affect Learning Johnson Chapter 11 Many Factors Affect Learning

Learn by Practice Frequency Regularity Precision

Gulf of Execution Gap between To minimize the gulf of execution What the tool supports What the user wants to do To minimize the gulf of execution Figure out what users want to do (Task Analysis) Construct a conceptual model Concepts the user needs to understand Tasks the user wants to perform UI = content model + control model + widgets

Examples of Execution Gulfs If you want to call someone not on your phone list, your must look up their telephone number You want to make a two-sided copy of a two-sided document, but the copier only makes single-sided copies You want to travel to Joe’s, so you must look up Joe’s address and enter it into the direction system

But… Extending the features means More time needed to implement More UI complexity More time to learn to use the system More UI errors

Simplify the content model UI = content model + control model + widgets Combine objects undergraduate students graduate students Combine operations selecting an address by pointing to a location on a map entering the state, county or town Avoid overlapping concepts Membership: company paid for customer-support service Subscription: company had subscribed to a customer-support newsletter Access: which areas of a web site user in a company could access Entitlements: services provided for each membership level

Simplify the control model UI = content model + control model + widgets Object Cut Paste Text CTRL-X CTRL-Y Sketch Table Image Video Object Cut Paste Text CTRL-X CTRL-V Sketch Table CTRL-Z Image CTRL-M CTRL-R Video CTRL-Q CTRL-D

Simplify the widgets UI = content model + control model + widgets Use the same type of widget for each of type of action. Text editing (Keystrokes and pointer movements) are the same regardless of the context in which text is being edited Opening documents Following links Choosing from a menu Clicking buttons Scrolling Foster growth of “muscle memory” (motor habits)

Terminology Task oriented Familiar Consistent

Familiar Termonology Value undefined (result of expression ghifXSLdoc.load) is not object The request is not valid in the current state Please Select Database: Iraq Afghanistan

Consistent terminology? Home page, main page Replace Color, paint bucket User identifier, password

We learn faster when risk is low Prevent errors when possible Deactivate invalid commands Make errors easy to detect by showing users clearly what they have done Allow users to undo, reverse or correct errors easily

Many Factors Affect Learning Summary Base on user’s goals and tasks (not on the implementation of the system), conceptually simple, and consistent Vocabulary is familiar to users, based on that of the task domain, and is used consistently Provide a low-risk environment in which errors are difficult to make and low in cost and easy to correct