Question

Interpreting the Strength of Correlation
Brett’s teacher observed Brett’s behavior in class for a week and compared the minutes he stayed on task in class to the grade he earned on the homework that night. She found that the correlation coefficient was r = 0.97.

What type of relationship has his teacher discovered?

positive correlation, likely causal
positive correlation, not likely causal
negative correlation, likely causal
negative correlation, not likely causal

Answer 1

positive correlation, not likely causal

r = 0.97 indicates a very strong positive relationship (more on-task minutes associated with higher homework grades). However, correlation alone does not prove causation — the teacher's observation is observational and could be affected by confounding variables (ability, prior knowledge, motivation, help at home, etc.).