Final answer:
Special study courses might help improve SAT scores. The statement that 30 students had an average gain of 60 points on the SAT after taking a special study course doesn't prove causation because the sample may not be representative, improvements can be due to other factors, and there's no comparison with a control group.
Step-by-step explanation:
Special study courses might help improve SAT scores, but the claim that the 30 students tutored had an average gain of 60 points does not conclusively prove the effectiveness of the course. Several reasons might explain why this increase does not necessarily mean the special course caused the scores to go up. The sample size of 30 students may not be representative of all students taking the SAT, and the improvement could be due to other factors such as students' familiarity with the test format or their test-taking strategies improving with experience. It's also possible that the students who chose to participate in the course were already more motivated and likely to study harder, which could contribute to an improvement in their test scores independent of the course's impact.
Additionally, without a control group of students who did not take the course for comparison, we cannot rule out the possibility that students might have achieved a similar score gain without the special course. It's important to consider factors like selection bias, the placebo effect, and regression toward the mean when evaluating the effectiveness of special study courses for the SAT.