Hi all,
I need calculate fixed effect with ancova analysis (spss or genstat).
My experiment was on fishes growth with differents diets (8): 15 fishes in each tank (each diet in triplicated, 3 tanks for each diet, total tanks:24). I need calculate p value for fixed effect: tanks and diets wit ancova analysis. whe i do it with just one effect (tank or diet separatedly) i found significants differences (this is the expected result), but when i do the analysis with both effect in the same ancova analysis (the correct method) i dont found significant diferences in diet...
I did read that the correct methos for this kind of problem coul be with blocks or nested method or just interaction tanks*diet
Any recomendation is valuable.
Thanks
Rodrigo
I need calculate fixed effect with ancova analysis (spss or genstat).
My experiment was on fishes growth with differents diets (8): 15 fishes in each tank (each diet in triplicated, 3 tanks for each diet, total tanks:24). I need calculate p value for fixed effect: tanks and diets wit ancova analysis. whe i do it with just one effect (tank or diet separatedly) i found significants differences (this is the expected result), but when i do the analysis with both effect in the same ancova analysis (the correct method) i dont found significant diferences in diet...
I did read that the correct methos for this kind of problem coul be with blocks or nested method or just interaction tanks*diet
Any recomendation is valuable.
Thanks
Rodrigo