I have an experimental design as follows:

Three groups of cakes: treatment A, treatment B, control;

Three replicates per cake.

They are observed during 10 days for microbial growth.

My interest is in evaluate their resistance to microbial growth, that is, if they differ in the amount of microbial growth during the experiment.

My question is:

To evaluate that which statistical analysis strategy must I use? (and would you check my suggestions of R code as well for the given options?)

1. two-way ANOVA (cake treatment (means of replicates) vs. days); [equivalent in R: microbial_amount ~ treatment*days]
2. three-way ANOVA (cake replicate vs. cake treatment vs. days) or [equivalent in R: microbial_amount ~ treatment*days + replicate]
3. Another type of ANOVA (nested ANOVA, repeated measures ANOVA, I'm not sure yet...)

Thanks!

I have an experimental design as follows:

Three groups of cakes: treatment A, treatment B, control;

Three replicates per cake.

They are observed during 10 days for microbial growth.

My interest is in evaluate their resistance to microbial growth, that is, if they differ in the amount of microbial growth during the experiment.

My question is:

To evaluate that which statistical analysis strategy must I use? (and would you check my suggestions of R code as well for the given options?)

1. two-way ANOVA (cake treatment (means of replicates) vs. days); [equivalent in R: microbial_amount ~ treatment*days]
2. three-way ANOVA (cake replicate vs. cake treatment vs. days) or [equivalent in R: microbial_amount ~ treatment*days + replicate]
3. Another type of ANOVA (nested ANOVA, repeated measures ANOVA, I'm not sure yet...)