Ego depletion refers to the idea that we have a limited amount of self-control, which can be depleted. Exerting self-control in one situation will make it harder to exert self-control on later tasks. For example, maybe you’re eating a healthy diet and successfully avoided the holiday cookies at work, but then couldn’t resist the holiday cookies your grandparents sent you. Singh and Göritz (2018) investigated whether ego depletion interferes with working memory performance and found no statistically significant difference in working memory between an ego-depleted group and a control group at an alpha level of .05. The total sample size for their study was N = 1385. The researchers ran a power analysis to determine whether their study, with this large sample, would have had enough power to detect even a small effect. That is, they were trying to determine whether they rejected the null in error. The power analysis determined that their study had a power of 0.98 to detect a small effect.

a. Is it likely that Singh and Göritz made a Type II error? Why or why not?

b. What is the probability that Singh and Göritz made a Type I error?