If the results of research are determined to be statistically significant, which statement is true?

• A. They differ from what would be expected based upon chance alone
• B. They prove treatment works in all populations
• C. They have no relation to sampling error
• D. They guarantee practical significance

Answer: (A)

Statistical significance means the observed difference or effect is unlikely to have occurred by chance if there were truly no effect (the null hypothesis). It indicates that the result differs from what would be expected based on chance alone, given the chosen probability threshold. This does not mean the treatment works in every population, nor does it remove sampling error—sampling variability is still a factor, and significance depends on the sample and the alpha level used. It also does not guarantee practical significance; a result can be statistically significant yet have a small or trivial real-world impact. So the truth is that the results are unlikely to be due to chance alone.