A researcher tests the effect of a new laparoscopic treatment for chronic shoulder dislocation, comparing it with an older treatment. The results are statistically significant, and the researcher states in the study findings that there is evidence that the treatment has promise for widespread application. A subsequent replication study fails to show statistical significance. A third and fourth study produce the same effects as the second. Sample sizes are determined to be sufficient in all four studies. What is the most likely explanation here?

Question

Quizplus · Accepted Answer

A Type I error occurs when a study incorrectly rejects the null hypothesis, suggesting a treatment effect when there is none. The initial study showing significance, followed by three replication studies failing to show significance, suggests the first study may have falsely identified an effect, indicative of a Type I error.

A Researcher Tests the Effect of a New Laparoscopic Treatment