Average Estimates in Line Graphs Are Biased Toward Areas of Higher Variability

Fuente: arXiv
Enregistré dans:
Détails bibliographiques
Auteurs principaux: Moritz, Dominik, Padilla, Lace M., Nguyen, Francis, Franconeri, Steven L.
Format: Preprint
Publié: 2023
Sujets:
Accès en ligne:
Tags: Ajouter un tag
Pas de tags, Soyez le premier à ajouter un tag!
_version_ 1866909343578849280
author Moritz, Dominik
Padilla, Lace M.
Nguyen, Francis
Franconeri, Steven L.
author_facet Moritz, Dominik
Padilla, Lace M.
Nguyen, Francis
Franconeri, Steven L.
contents We investigate variability overweighting, a previously undocumented bias in line graphs, where estimates of average value are biased toward areas of higher variability in that line. We found this effect across two preregistered experiments with 140 and 420 participants. These experiments also show that the bias is reduced when using a dot encoding of the same series. We can model the bias with the average of the data series and the average of the points drawn along the line. This bias might arise because higher variability leads to stronger weighting in the average calculation, either due to the longer line segments (even though those segments contain the same number of data values) or line segments with higher variability being otherwise more visually salient. Understanding and predicting this bias is important for visualization design guidelines, recommendation systems, and tool builders, as the bias can adversely affect estimates of averages and trends.
format Preprint
id arxiv_https___arxiv_org_abs_2308_03903
institution arXiv
publishDate 2023
record_format arxiv
spellingShingle Average Estimates in Line Graphs Are Biased Toward Areas of Higher Variability
Moritz, Dominik
Padilla, Lace M.
Nguyen, Francis
Franconeri, Steven L.
Human-Computer Interaction
We investigate variability overweighting, a previously undocumented bias in line graphs, where estimates of average value are biased toward areas of higher variability in that line. We found this effect across two preregistered experiments with 140 and 420 participants. These experiments also show that the bias is reduced when using a dot encoding of the same series. We can model the bias with the average of the data series and the average of the points drawn along the line. This bias might arise because higher variability leads to stronger weighting in the average calculation, either due to the longer line segments (even though those segments contain the same number of data values) or line segments with higher variability being otherwise more visually salient. Understanding and predicting this bias is important for visualization design guidelines, recommendation systems, and tool builders, as the bias can adversely affect estimates of averages and trends.
title Average Estimates in Line Graphs Are Biased Toward Areas of Higher Variability
topic Human-Computer Interaction
url https://arxiv.org/abs/2308.03903