C955 Applied Probability and Statistics - Set 5 - Part 3

Correct Answer: The effect may be real but too small to matter practically

Very large samples can detect trivially small effects as significant, so the practical importance of the difference must be judged separately from significance.

Correct Answer: Repeating a study to confirm whether results hold

Replication repeats a study, ideally by independent researchers, to check whether findings are reproducible rather than due to chance or particular conditions.

Correct Answer: A single significant result may be a chance occurrence

Because significance thresholds allow some false positives, consistent replication provides much stronger evidence that a finding is genuine rather than a fluke.

Correct Answer: Manipulating analysis until a significant result appears

P-hacking involves trying many analyses or selectively reporting until a significant p-value emerges, which invalidates the meaning of the significance threshold.

Correct Answer: Each test carries its own chance of a Type I error

With many independent tests, the probability that at least one produces a false positive by chance rises substantially, requiring correction for multiple comparisons.

Correct Answer: Providing a baseline to separate the treatment effect from other influences

The control group shows what happens without the treatment, so comparing it to the treatment group isolates the treatment's actual effect from other factors.

Correct Answer: The ability to critically evaluate data-based claims and their limitations

Statistical literacy enables people to interpret data claims critically, recognizing bias, uncertainty, and the difference between correlation and causation rather than accepting figures uncritically.

Correct Answer: Association alone cannot establish that one variable causes another

Observing that two variables move together does not establish a causal link, because confounding, reverse causation, or chance may explain the association.

Correct Answer: The mean is multiplied by that same constant

Scaling every value by a constant scales the mean by the same factor, since the mean is a linear function of the data values.

Correct Answer: 1

A certain event has probability 1, the maximum on the probability scale, meaning it will definitely happen.