What are the confounding variables in this study, if there are any? An industrial/organizational psychologist is interested in how team size influences effectiveness on a puzzle task. A sample of participants were randomly assigned to complete a puzzle in teams of either 2 (n = 5), 4 (n = 5) or 6 (n = 5). The amount of time it took each team to complete the puzzle was measured. Participants in the team of 2 condition completed a word-search task, participants in the team of 4 condition completed a crossword puzzle task, and participants in the team of 6 condition completed a number puzzle similar to Sudoku.