Background

For years, teachers and educators have been coming up with various ways to teach their students so that the material sticks so that students are more likely to learn and recall information when they need it during exams, tests, and in real life experiences. In general, they have two choices of how to do this: The Meshed Approach and the Before Approach. A study was performed to determine whether the Meshed or Before approach had any positive benefit on memory recall. From the data, we can see which approach is more beneficial for the students in retaining and recalling information.

Using the Wilcoxon Rank Sum(Mann-Whitney) Test, we can analyze this hypothesis with the level of significance at 0.05:

\(H_0: \text{difference in medians} = 0\)

\(H_a: \text{difference in medians} \neq 0\)


Analysis

The following QQ Plots show the distribution of sample data for the Before and Meshed approaches. From the plots, we can see that the data is skewed due to the shape of the slope. This tells us that most the data points are lined up within the boundaries, with a few outliers. There were a couple points that did not completely line up with the slope line and they are significant enough to skew the data.

par(mfrow=c(1,3))
qqPlot(Friendly$correct[Friendly$condition == "Before"], dist="norm", id.method="y", ylab="Before", labels=rownames(Friendly))
qqPlot(Friendly$correct[Friendly$condition == "Meshed"], dist="norm", id.method="y", ylab="Meshed", labels=rownames(Friendly))
qqPlot(Friendly$correct[Friendly$condition == "SFR"], dist="norm", id.method="y", ylab="SFR", labels=rownames(Friendly))