A Fine Line: Target Slope and Similarity of Distractors' Effect on Extremum Trend Spotting. (September 2015)

• Record Type: Journal Article
• Authors: Stokes, Thomas A.; Gillan, Douglas J.; Strauss, Jemma M.
• Is Part Of: Proceedings of the Human Factors and Ergonomics Society ... Annual Meeting. Volume 59:Part 1(2015)
• Page Start: 1525
• Page End: 1529
• Publication Date: 2015-09
• Subjects: Human engineering -- Congresses; 620.8205
• DOI: 10.1177/1541931215591330
• Languages: English
• ISSNs: 1541-9312

Abstract

Trend lines are a powerful visualization tool for displaying data over a period of time. Previous research has shown that trend lines are encoded as a single object containing one value (a slope for linear trends), but the exact mechanics of how trend stimuli are processed is not well known. The present research set out to determine what factors impact comparisons between trend line slopes and what is the visual and cognitive process that underlies these comparisons. Results suggest that there may be a two-phase process when searching for an extremum in a set of trend lines, where during an initial phase a person will search the stimuli based on a mental anchor to identify candidates, and then make direct comparisons between those competitors during a second phase. This trend holds true whether a person is searching for the steepest or least steep slope in a set of trend lines. This result has instant applications to visualization designers who use slope as a feature in their graphics, and is especially important when choosing x/y axis aspect ratio as this choice directly transforms presented slope.