I have two groups of mice (n= 6 per group), treatment and control. I am measuring tumour size of these mice every day for 3 weeks. The size will be averaged in each group and I am plotting it over a X and Y axis graph (X = timelines, Y = Tumour size). If I want to show if there is any difference in the tumour volumes between the treatment and control group over the 3 weeks of experimental period, what kind of statistical test can I use?
I was initially thinking of using student's t-test at each time-point for 3 weeks, but I was advised that this would be less powerful, and student's t-test should be used when you want to know the statistical difference between the two groups at "one time-point', rather than multiple time-points.
Any suggestion would be greatly appreciated.
ANOVA is the classic answer. A simple Bonferoni correction applied to the T test is a easy start. The most an acceptable is a T test for repeated measures. aka muliple sample T test Basically you have to adjust for the non-independent variance of repeated measurements of the same sample.
Perform a two way Analysis of Variance (ANOVA) test. This will be perfect.
Best you Apply one way Anova, since you have to test the difference in between the groups. Two way analysis would be preferable if you also wish to test that within the groups.