Ttests using Excel Comparing group means under 2

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T-tests using Excel • Comparing group means under 2 conditions • Different people (between

T-tests using Excel • Comparing group means under 2 conditions • Different people (between group design) • On ground vs online • Test score data example • The means differ, but is it significant?

T-tests using Excel • Excel command - ttest(array 1, array 2, tails, type) •

T-tests using Excel • Excel command - ttest(array 1, array 2, tails, type) • Choose 1 or 2 tails • 1 means the hypothesis is directional - e. g. , predicting the 2 nd set is higher than the 1 st • 2 means you aren’t sure, or you are predicting either • Choose type • 1= paired or within group/repeated measures • 2= 2 samples with equal variance between group • Test using an “F-test 2 sample for variance” in excel • 3= 2 samples with unequal variance between group • Assume unequal variance unless you have tested it • So for our example • =ttest(B 5: B 24, C 5: C 24, 2, 3) • If “ 2 samples”, check for equal variance using f test command • ftest(array 1, array 2) • If p>. 05, the variances of the two populations are unequal so use #3

T-tests using Excel Comparing group means under 2 conditions On ground vs online P>.

T-tests using Excel Comparing group means under 2 conditions On ground vs online P>. 05, so no statistically significant difference between the two groups

Running a T-test in Excel On ground vs online Test scores This time, p<.

Running a T-test in Excel On ground vs online Test scores This time, p<. 05, so there is a statistically significant difference between the two groups

Chi-Square in Excel example • Assume you have applied a rubric to determine whether

Chi-Square in Excel example • Assume you have applied a rubric to determine whether students have met your program standards for an outcome • Compare online and on ground to see if they differ significantly in their success