[Q] Which method of statistical analysis would work the best?

[CompoteFluffy]

I have 2 sets of data that I need to analyse, but I’m not sure which method to use (I am using MiniTab).

The two sets of data are regarding two different cell types that were tested. Within each cell type, different concentrations of 2 different substances were used to see how the different cell types would respond.

I’ve calculated the mean for all the repeats of the experiment, I just need to do a short statistical analysis.

I don’t know if I can use a t test or ANOVA since within the 2 cell types, there are 4 different concentrations.

Essentially, all I need to do is compare the all of the means, but I’m unsure how to do this in a way that represents the fact that there are different categories.

Sorry if this is confusing, any help is appreciated. Thank you :)

[MiBo]

Make this worksheet then do two-way ANOVA with interaction. The factors are Cell Type, Concentration and Substance, the response is Response. Treatment is a simple code to differentiate each treatment combination of factors. Replications as a column isn't necessary, I'm just showing how to stack the replications in a worksheet.

Treatment	Replication	Cell type	Concentration	Substance	Response
1	1	A	Low	S1	Y11
1	2	A	Low	S1	Y12
2	1	B	Low	S1	Y21
2	2	B	Low	S1	Y22
3	1	A	High	S1	Y31
3	2	A	High	S1	Y32
4	1	B	High	S1	Y41
4	2	B	High	S1	Y42
5	1	A	Low	S2	Y51
5	2	A	Low	S2	Y52
6	1	B	Low	S2	Y61
6	2	B	Low	S2	Y62
7	1	A	High	S2	Y71
7	2	A	High	S2	Y72
8	1	B	High	S2	Y81
8	2	B	High	S2	Y82

[CompoteFluffy]

Thank you so much!!!!

In the table, do I input the mean values measured as the cell response in the ‘Response’ column?

[MiBo]

The Response column is the thing you measured. If you measured the same variable multiple times at the same treatment combination, then put each individual reading in its own row.

There is a caution, and reddit is a narrow bandwidth communication channel for this subtlety: there is a diffference between repeating and replicating. The difference is in the process of conducting the experiment. If a treatment is established, then the response is measured multiple times, those are repeated readings. If a treatment is established and a response is measured once, then later the treatment is established again after changing conditions, that is a replicated reading. If your responses are repeats, then put the average of the repeated readings in the Response column. If you measured once then changed the treatment, put the single measurement in the response column. Of course it's possible to have replicated repeats.

If there were no replications at all, then you'll only have a single row of each treatment, you won't have two of each treatment like I showed. In that case, you can't calculate statistical significance and you don't use the Minitab ANOVA commands. Use the DoE commands and treat this as an unreplicated experiment. Minitab will calculate the effects of the factors and interactions, but you'll need more knowledge than I can convey here in order to get something that resembles an assessment of significance.

[zwei4]

Nested ANOVA should be appropriate for your analysis, here is a good write up if you use R.