David K. FarkasHCDE

University of Washington

“Scent and Situation Awareness”

What is situation awareness?

• Navigating a website is similar to wayfinding in the physical world

• We use landmarks, we remember our route, we build a mental model

• On the Web we are generally navigating hierarchies

Understanding your location in a hierarchy

Users differ in how fully they utilize situation awareness

• Depends on the individual user

• Depends on a user’s goals and circumstances

• Depends on the website (small vs. large)

• Users may prefer “opportunistic” navigation

For large websites situation awareness is limited

What is “scent”?

• Navigation is similar to the behavior of foraging animals (Pirolli and Card)

• Links (metaphorically speaking) give off a scent that users may choose to follow

• Scents must be distinct

• A strong scent is more apt to attract users

Distinctiveness and strength

Visualizing scent

What “scent” really means

• Scent is a metaphor for confidence

• Scent captures a trade-off that characterizes all user navigation: motivation vs. confidence level plus projected effort

• A distinct scent means the user has confidence regarding ultimate success

• A strong scent means the goal is near—little effort will be required

Take-aways

1. Situation awareness: Navigating a website is akin to wayfaring in the real world

2. Design for situation awareness, but recognize its limitations

3. Scent is a metaphor for the user’s cost- benefit analysis when following links

4. Require distinct scents—links must point clearly to their destinations

5. Try for strong scents but users will follow a weak scent if it is distinct