Question

An industrial engineer ran a study to determine whether a training program improved productivity. 200 workers participated in the study. The study concluded that workers who had the training were more productive. However , in fact there was no difference. What type of error has been made: Type I error or Type II error?

Answer 1

The study erroneously concluded that training improved productivity when there was no actual difference, indicating a Type I error was made where a true null hypothesis was wrongly rejected.

Step-by-step explanation:

The student is concerned with identifying whether the error made in the study, where the conclusion was that training improved productivity when in fact there was no difference, is a Type I error or a Type II error. In hypothesis testing, a Type I error occurs when a true null hypothesis is wrongly rejected. This is exactly what happened in the study:

• The null hypothesis would be that the training does not improve productivity.
• The study concludes, incorrectly, that the training does improve productivity.
• Therefore, the study has committed a Type I error by rejecting the true null hypothesis.

In summary, a Type I error involves concluding there is an effect when there isn't one, while a Type II error involves failing to identify an effect when there is one. The study in question committed a Type I error.