W5 Flashcards
What is a t-value?
It’s a measure that combines the magnitude of difference between groups with our confidence in the estimate. It’s influenced by both effect size and sample size.
Define effect sizes.
Effect sizes, such as Cohen’s d, represent the size of the difference between groups. Cohen’s d is not influenced by sample size; a larger Cohen’s d indicates a larger effect. Effect sizes provide information about the magnitude of the difference but not the confidence in the estimate.
What is a p-value?
Answer: It’s the probability of observing a difference at least as large as the one in your dataset, assuming the null hypothesis were true (by chance). It’s conventionally considered significant at p < 0.05.
What are degrees of freedom (DF), and how do we calculate them?
Degrees of freedom are an adjustment to account for the number of values estimated from data, which is one less than the number of observations. For one-sample and paired sample t-tests, DF = N - 1. For independent sample t-tests, DF = N1 + N2 - 2.
