What is the “third-variable problem”?  

  A researcher asked college students which Hogwarts house (Gryffindor, Slytherin, Ravenclaw, Hufflepuff) best matched their personality. The researcher wanted to know whether preferences were evenly distributed across houses and conducted a chi-square goodness-of-fit test. Analysis revealed a Cramer’s V of .42 for this study. Which of the following is the best interpretation of this effect size?  

  If you are comparing student test scores across three different teaching methods, how many levels does the factor have?  

  A researcher calculates Cohen’s d = 0.80 for a study comparing two groups. How should this effect size be interpreted?  

  If you are comparing student test scores across three different teaching methods, how many levels does the factor have?  

In a scatterplot, each dot typically represents  

What does the denominator of the correlation coefficient formula represent?  

  Which condition should be met before conducting a post hoc test in a one-way ANOVA?  

  What is the null hypothesis in a chi-square goodness-of-fit test?  

What is the typical range for a correlation coefficient (r)?