A researcher wanted to determine if teaching approaches influence second graders' ability to do columnar addition. To test this, the researcher randomly selected 75 second graders from a local school and assigned them to one of three teaching conditions: (1) rote memory, (2) manipulatives, or (3) computer. One group of 25 students were taught using rote memory, a second group of 25 students was taught using manipulatives, and a third group of 25 students was taught with a calculator. All students were given a test on columnar addition. The means and standard deviations for the three groups are shown below.
Mean Number of Correct Answers for Three Groups of Second Grade Students on a Test of Columnar Addition
Group | n | M | SD
---|---|---|---
Rote Memory | 25 | 4.00 | 2.24
Manipulatives | 25 | 9.00 | 3.08
Calculator | 25 | 17.00 | 2.74
What hypothesis testing technique should the researcher use to analyze the data?
A. ANOVA
B. Paired t-test
C. Two-sample t-test
D. z-test for the population mean