Greetings All,
I'm currently analysing data resulting from a study of children's reading
ability. The study involves two treatments and each child's reading ability
was measured before and after the application of one of the treatments.
Thus, each child received one or the other (but not both) of two possible
treatments. The children are divided into two groups:
Weak readers: those whose pre-treatment reading score was less than the mean
pre-treatment reading score
Strong readers: those whose pre-treatment reading score was greater than the
mean pre-treatment reading score
Anyhow, I would like to test (for each treatment) whether or not the change
in the reading score (Post-treatment score - Pre-treatment score) is the
same for weak readers and strong readers. I have atempted to test this by:
1. Creating a new variable, "Change"
Change = Post-treatment score - Pre-treatment score
2. Using a two-sample t-test to determine whether or not the mean value of
"Change" measured over the weak readers is significantly different from the
mean value of "Change" measured over the strong readers
However, I am not certain that this is the best way to test my hypothesis,
if anyone can suggest a better way, I'd be very grateful for their
assistance.
Similarly, I'd like to test whether or not the change in the reading score
is the same for each treatment. I have attempted to test this by:
1. Creating a new variable, "Change"
Change = Post-treatment score - Pre-treatment score
2. Using a two-sample t-test to determine whether or not the mean value of
"Change" measured over treatment A is significantly different from the mean
value of "Change" measured over treatment B
Again, if anyone knows of a better way of performing this test, I'd be very
appreciative if they would let me know about it.
Thanks in advance,
Dónal.
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