Blog

What conclusion can you draw from the result of the t-test presented below?  

There are two sources of error contributing to the standard error in the denominator of the independent samples t-test equation.

How do sample size and sample variance influence measures of effect size, such as Cohen’s d?

Do college students preform worse in online courses? To answer this question, a researcher compared the test scores of students enrolled in online vs. in person class. Their scores are presented in a table below. Using a one-tailed test with α = .05, what conclusion should be made? 

What do you do when the homogeneity of variance assumption is violated in a t-test?

Which of the following confidence intervals (i.e., 1, 2, 3, and 4) indicate a significant mean difference between two groups? Please explain how you know.

State the null and the alternative hypotheses using symbols. 

Suppose a researcher wants to decrease the width of the confidence interval. What are two ways in which this can be accomplished?

Compute Cohen’s d to measure the size of the effect in the study in Q20. d = [color1]

The pooled variance will be closer to whichever variance is larger, regardless of the sample sizes.