Exam 2 Flashcards
Type 1 Error (Alpha)
When you reject the null hypothesis when it should of been accepted
Type II Error (Beta)
When we accept the null hypothesis when it should of been rejected
What is the most common alpha value
0.05
What is the most common beta value
0.20
What is power
1-beta so in this case it is 80% to detect a significant effect
Factors that affect power
Sample Size, Mean Difference (best to have a big mean difference), Variability (best to have a bigger variability)
What is the distribution of sample means
set of means from all the possible random samples of a specific size from a population
What is the importance of the distribution of sample means
serves as a bridge from the sample we have to the population
What does the central limit theorem tell us
the mean of a group is the same as the population mean, distribution of sample means is going to be normal as long as our sample is big enough, measuring things in terms of standard error instead of standard deviation
What is the importance of central limit theorem
Allows us to relax the assumption of normality
When do you use a one sample t test?
When you have a mean
When do you use a z test
When you have a mean and standard deviation of the population
One Sample T Test hypotheses
Ho: μsub group = average
H1: μsub group does not equal average
One Sample T Test and Z test assumptions
normality, dependent variable is scalar, independent random sample
When do you use an independent sample t test
when you have two different groups
