→ Random assignment

Is the difference between groups based on how they were formed or can we discount that as a reasonable explanation?
 Example: Psychological study whether participants were more creative after thinking of their intrinsic vs extrinsic motivation for writing
 Only calculating the mean fails to account for variability within each group
 Variability can be measured with the standarddeviation

If we assign participants to groups randomly, is it possible that an “unlucky random assignment” has an influence on the mean result?
 Example: Shuffle creativity scores and randomly assign to group, then calculate how often the mean creativity score for intrinsic and extrinsic motivation changes over, say, 1000 trial runs → New pvalue

Keywords: Statistics