Model of Visual Search and Selection Time in Linear Menus (CHI'14)

This paper presents a novel mathematical model for visual search and selection time in linear menus. Assuming two visual search strategies, serial and directed, and a pointing sub-task, it captures the change of performance with five fac- tors: 1) menu length, 2) menu organization, 3) target posi- tion, 4) absence/presence of target, and 5) practice. The novel aspect is that the model is expressed as probability density distribution of gaze, which allows for deriving total selec- tion time. We present novel data that replicates and extends the Nielsen menu selection paradigm and uses eye-tracking and mouse tracking to confirm model predictions. The same parametrization yielded a high fit to both menu selection time and gaze distributions. The model has the potential to im- prove menu designs by helping designers identify more ef- fective solutions without conducting empirical studies.

Total selection time as a gaze distribution that is the sum of three components: Serial search, Directed search and Pointing

The effects of target position (left panels) and organization, and practice interaction (right panels) on selection time

Observed (solid) vs. predicted (dash) menu selection time per target, organization length for the first and last block.

Two cursor control strategies for selecting the target 13 (dark grey). Left: The cursor (solid) trails the eyes gaze (dash). Right: A single mouse move when the target has been localized
Proportion of three cursor movement strategies: trailing (on the target +/- 0.5 items), single move (top of the menu; +/- 0.5 items), and intermediate (between)
Gaze distribution for the target 3 and 11 aggregated across users. The plot shows that gaze occurs also in the vicinity of the stimulus (above the menu).
Observed vs. predicted menu selection times by menu organi- zation, menu length an practice.
Actual (solid) and predicted (dash) gaze distribution aggre- gated accross all participants for the unordered organization at the block 1 (black) and block 4 (grey).