Ranked by importance of document as calculated by some algorithm (e.g., Google PageRank) Duplicates shown separately or merged into a single record ...
Wednesday, November 16
No discussion class
Thursday, November 17
No office hours
Grades were returned yesterday
If you have any questions, send email to email@example.com
Replies may be delayed until next week
Example: Design an interface for a simple fielded search.
Interface: Fill in boxes, text string, ... ?
Presentation of results ... ?
Manipulation of results ... ?
Functions: Specify field(s), content, operators, ... ?
Retain results for manipulation ... ?
Query options ... ?
Data: Metadata formats ... ?
Data structures and file structures ... ?
Systems: Performance ... ?
Requirements (needs of users and other stakeholders)
Implementation (may be prototype)
Design (creative application of design principles)
What is usability?
Usability comprises the following aspects:
From ISO 9241-11
Assessing systems using established theories and methods
Analysis of results
Testing the system, not the users!
Stages of evaluation with users:
User testing is time-consuming and expensive.
“The user can find the required information in no more than 2 minutes”
“Answer the question: how hot is the sun?”
Use the descriptions of users from the requirements phase to detect potential users
Concept: monitor users while they use system
Analysis of system logs
• Which user interface options were used?
• When was was the help system used?
• What errors occurred and how often?
• Which hyperlinks were followed (click through data)?
• Complaints and praise
• Bug reports
• Requests made to customer service
Designers and evaluators need to work as a team
Designers are poor evaluators of their own work, but know the
requirements, constraints, and context of the design:
• Some user problems can be addressed with small changes
• Some user problems require major changes
• Some user requests (e.g., lots of options) are incompatible with other requests (e.g., simplicity)
Do not allow evaluators to become designers
The order in which the hits are presented to the user:
• Ranked by similarity of match (e.g., term weighting)
• Sorted by a specified field (e.g., date)
• Ranked by importance of document as calculated by some algorithm (e.g., Google PageRank)
• Duplicates shown separately or merged into a single record
• Filters and other user options
What impact do these choices have on the usability?
• 10 information seeking tasks in 2 categories
• Users randomized across tasks
• Click-through data to see what the user did
• Eye tracking data to see what the user viewed
• Google results presented with top ten ranks reversed
An example of interdisciplinary information science
research by Cornell's Human Computer Interaction
Group and Computer Science Department
Number of users who clicked on link
Rank of hit
Number of users who viewed short record before first click
Rank of hit
Part of short record viewed before first click (% of users)
Other: 8.2%(includes, cached, similar pages, description)
Percentage of users who clicked on link
Rank of hit