A researcher conducts a study measuring 20 children before and after they play violent video games and obtains a value of 1.98 for the t-statistic. For a non-directional alternative hypothesis, which of the following is the correct way to present this analysis?
A) t(20) = 1.98, p .05
B) t(19) = 1.98, p .05
C) t(18) = 1.98, p .05
D) t(38) = 1.98, p .01

Question

A researcher conducts a study measuring 20 children before and after they play violent video games and obtains a value of 1.98 for the t-statistic. For a non-directional alternative hypothesis, which of the following is the correct way to present this analysis?
A) t(20) = 1.98, p > .05
B) t(19) = 1.98, p > .05
C) t(18) = 1.98, p > .05
D) t(38) = 1.98, p > .01

Quizplus · Accepted Answer

Since the researcher is measuring the same group of children before and after playing violent video games, this is a paired-samples t-test. Therefore, the degrees of freedom are n-1, where n=20, resulting in 19 degrees of freedom. Additionally, the t-statistic of 1.98 falls above the critical value of 2.093 for a two-tailed test with 19 degrees of freedom at alpha level .05. Therefore, the p-value must be greater than .05. Therefore, the correct way to present this analysis is: t(19) = 1.98, p > .05.

A Researcher Conducts a Study Measuring 20 Children Before and After