This sketch gives some accompanying visuals for a discussion about significance testing. This could be particularly valuable to students finding it difficult to grasp the quantities described by a Type I Error (rejecting the Null Hypothesis when it is correct) or a Type II Error (Accepting the Null Hypothesis when a particular alternative is correct). The sketch allows the student to change the value of alpha and the value of standard deviation sigma, and thereby discover the costs of controlling either type of error. This sketch includes the confidence interval sheet from the "Normal Distribution and Z-scores" sketch.
Keywords: normal distribution, normal curve, mu, sigma, mean, standard deviation, z-score, probability, density curve, standardize, standard normal, normal random variable, confidence interval, CI, z*, statistics, statistically significant, p-value, alpha, one-sided, two-sided, z-test, null hypothesis, H0, Ha, alternative hypothesis, type i error, type 1 error, type ii error, type 2 error, power