practical statistics for non-stats geeks

#UXPA2016www.uxpa2016.org

Session Survey: http://www.uxpa2016.org/session/survey/267Conference Survey: www.uxpa2016.org/survey

Practical Statistics for Non-Stats

GeeksTom Tullis & Mikey Case

May 31, 2016



Introductions

Senior User Experience ResearcherFidelity [email protected]

VP, User Experience ResearchFidelity [email protected]



Sample Study: Types of Charts

One between-subjects variable:3D vs Flat

Four chart types:Bar, Column, Donut, Pie

Three task types:Estimate a value, Largest, Smallest

Two sets of data for each task

Total of 24 charts shown to each participant

Measured speed and accuracy

Seven subjective ratings at the end

http://www.surveygizmo.com/s3/2767833/UXPA-2016-Graphs



Sample Study Data1,424 participants!



Initial Analyses• Demographics• Gender: Pivot table• Age: Frequency distribution, Mean, Median, Mode• Color Vision by Gender: Pivot table

• Add Average Accuracy and Time columns• Detecting Cheaters• Detecting Outliers (time data)

• Cleaned Data: http://www.measuringux.com/UXPA2016/ StatsWorkshop/data/cleaned.xlsx

http://www.measuringux.com/UXPA2016/StatsWorkshop/data/cleaned.xlsx





Comparisons• 3D vs Flat: Means and Confidence Intervals:• Accuracy• Time

• By Chart Type:• Accuracy• Time• Efficiency

• Efficiency by Age Group• T-tests



Subjective Ratings• Likert Scales (Strongly Disagree . . . Strongly Agree)• Semantic Differential (e.g., Childish . . . Professional)• BERT (Bipolar Emotional Response Test)• Standardized Scales:• System Usability Scale (SUS)• Net Promoter Score (NPS)

• Categorical data (e.g., pick your favorite)



Card-sorting Data

practical statistics for non-stats geeks

Technology