Context
I need to compare two groups of students. Students of these groups did some work, which later was evaluated. Now I have the values of the accuracy of every student. Here are the results:
0.2 0.065 0.123 0.075 0.181 0.054 0.185 0.106 0.142
and
0.269 0.357 0.2 0.221 0.275 0.277 0.253 0.127 0.246
I would like to check if the first group was better in terms of accuracy than the second group. As the samples are small I thought about using t test to compare the samples.
H0 hypothesis was that the accuracy of both groups are equal
H1 hypothesis was that the accuracy of the 1st group was greater than the accuracy of the 2nd group.
I used the following R function:
t.test(precisionAdHoc$adhoc, precisionH4U$H4U, "g", 0, FALSE, TRUE, 0.95)
where precisionAdHoc$adhoc
holds the data from the first group and precisionH4U$4HU
holds the data from the second group.
I got the following result:
data: precisionAdHoc$adhoc and precisionH4U$H4U
t = -4.3687, df = 16, p-value = 0.9998
alternative hypothesis: true difference in means is greater than 0
95 percent confidence interval:
-0.1701334 Inf
sample estimates:
mean of x mean of y
0.1256667 0.2472222
Questions
- Did I use the
t.test
function correctly? If not, what did I get wrong? and how should I correct it? - If the function was correct, how should I interpret the results?