How do I interpret the Task Statistics in Preference Test?

In this help, we'll discuss how to use the Task Statistics analysis to:

  • View Task Statistics per task
  • Understand statistical significance of results

View Task Statistics per task 

  • This analysis displays Task Statistics one task at a time
  • Use the task selection dropdown list in the top section of the screen to switch to the task you want to analyze.
  • Alternatively, use the arrow buttons to the left and right of the dropdown list to move to the previous/next task.

For each task, Task Statistics contain the task's text and the list of designs included in the task. Each design includes the following data:

  • Design
  • Design label
  • Average completion time - How much time did this task take to complete to the respondents who picked this design
  • Percentage of respondents - What percentage of respondents picked this design
  • Number of respondents - How many respondents picked this design. Click to see a full list.

Understand statistical significance of tasks 

  • Statistical significance in a Preference Test tells you how much you can rely that the given result is the effect of respondents truly preferring it over the others. If statistical significance is low, it means the result has likely placed in first place only by chance.
  • The degree of statistical significance is calculated using Chi-Square Goodness of Fit Test.
  • You need to collect the number of respondents that is at least 5 times the number of tested designs in a task in order to properly calculate statistical significance.

Statistical significance is expressed as a percentage ranging between 0% (no statistical significance) and 100% (statistical significance absolutely guaranteed)

  • 99%-100% - The results are surely statistically significant
  • 95%-98% - The results are probably statistically significant
  • 90%-94% - The results tend towards statistical significance
  • 51%-89% - The results probably aren't statistically significant
  • 0%-50% - The results aren't statistically significant