Power and sample size — Flashcards

Flashcard 1: What is the t-test used for? (biostatistics)

Answer: Compare means of two groups. mnemonic: Mr. T is mean.

Flashcard 2: "β" with reference to statistical error

Answer: the probability of making a Type II statistical (false negative) error

Flashcard 3: power (epidemiology)

Answer: probability of detecting a differential effect if it is actually present

Extra: power = (1-β)

Flashcard 4: What is the relationship between standard error of the mean and standard deviation?

Answer:

Flashcard 5: In a normal distribution, how many data points fall within three standard deviations from the mean?

Answer: 99.7%

Flashcard 6: In a normal distribution, how many data points fall within two standard deviations from the mean?

Answer: 95%

Flashcard 7: In a normal distribution, how many data points fall within one standard deviation from the mean?

Answer: 68%

Flashcard 8: Phase II

Answer: Small number of individuals with the disease of interest

Extra: Efficacy, dosing, adverse effects