Pretend that we conduct a study, analyze the data, and conclude that there is a

Question

Pretend that we conduct a study, analyze the data, and conclude that there is a treatment effect. However, the reality is that there was no treatment effect. Perhaps our sample just had a mean that was unusually far from the population mean. What kind of error does this describe?

A researcher has developed a new treatment program designed to improve IQ. Let us assume that the treatment program really does work. The researcher tests the treatment plan by studying 4 children randomly selected from a nearby preschool. After completing the treatment protocol, he compares their IQs to the known population mean (100). He finds that the mean of his sample is not different enough from the population mean to allow him to reject the null hypothesis. What type of error has occurred?

Explanation / Answer

1. The reality is that there was no treatment effect. The Null hypothesis is: there was no treatment effect.

But data showed there is a treatment effect. So we have to reject the Null hypothesis when it is true.

This is a Type I error (Incorrect rejection of the Null Hypothesis when it is true).

2. The IQ improvement treatment program really does work.

The Null hypothesis is: IQ improvement treatment program does not work

After the data is analysed, the means are placed close by, so the researcher accepts the Null hypothesis.

This is s type II error (incorrectly retaining a false null hypothesis)

Related Questions

Navigate

• Browse (All)
• Browse P
• Subjects

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.