1. Many Factors Affect Learning
Johnson Chapter 11
Many Factors Affect Learning

2. Learn by Practice
Frequency
Regularity
Precision

3. 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

4. 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

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

6. 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

7. 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

8. 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)

9. Terminology
Task oriented
Familiar
Consistent

10. 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

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

13. 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

14. 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