Comparing several different means. Comparing four reading methods . Reading ages were obtained before and after the course of instruction. Students were classified into four groups, depending on which of the reading methods they said they had used when taking the second reading-age test.
Larger improvements do seem to be associated with the scanning or mapping.
The Analysis of Variance Table Suppose that there are treatment groups, and let be the sample mean for the th group. Reading methods . There are groups with Let be the sample size of the th group. Reading methods . The four sample sizes are Write for the th observation in the th group.