- Thread starter Nina_joon
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Next is you can have 3 factors in four runs like:

Code:

```
+1 +1 +1
-1 +1 -1
+1 -1 -1
-1 -1 +1
```

And you can have 7 factors in 8 runs. (But I am to lazy to write down the design).

If all variables are quantitative you can put the two extra in the center and use that as estimates of error and do significance tests.

And, j58 does not know your standard deviation or your effect size. If the std is 0.00001 and the effect is 100000, then your power will be pretty good.

I have 3 groups separated based on their background: in 2 of them, I have 3 participant and in the last one, I have 4 participants. Does this mean that I cannot use factorial anova?

Here is the detailed description of my study:

1- I have 3 groups with different background

2- Each group participated in 3 different phases to annotate some documents

Now, we want to know whether any of these groups performed better than the other in any of phases. we want to know if there is any difference based on the background as well as phases.

So, based on your description we cannot use factorial anova?

By definition, in a factorial ANOVA, you have at least 2 factors, with at least 2 levels each, and you randomize subjects to every combination of the levels of the factors. So, if factor A has levels a1 and a2, and factor B has levels b1 and b2, then in a factorial ANOVA you have subjects randomized to four groups: a1/b1, a1/b2, a2/b1, a2/b2. If you have more than 2 groups or groups with more than 2 levels, then there will be more than 4 groups, and subjects will be assigned to all of them.

The OP asked for the minimum, not what was resonable.

I searched internet to learn more about repeated-measures design such as, repeated measure anova.

It seems for these kind of designs, you need to have the "same measure" repeated several times. However, the participants of our study had different levels of training on how to annotate notes in each phase. So, we had training factor, in addition to background. So, I was wondering if you still recommend repeated measure design for our study.

Also, I need to mention that for each phase, we calculated the number of entities that each participant has annotated, as well as their accuracy level.