ANOVA 2x6 Question

#1
I'm looking at doing a project where I have participants view images of people with different emotional and facial expressions. I would display the image and time how long it takes to enter a response. The actors in the image would vary in ethinicity (caucasian or hispanic). plus the actors would have 6 different possible emotional expressions (anger, fear, disgust, happiness, sadness, or surprise)

After looking at my design and methodology, it looks like I would have 2(ethinicity) x 6 (emotional expression) ANOVA.

What are the drawbacks, of having a 2x6 ANOVA? Correct me if I'm wrong but if I remember correctly each additional factor in an ANOVA increases the error and requires more of an effect to find significance?
My concern is that with so many factors, one could argue the experiment would never be able to find significance.

Is there a different way of doing this experiment or analyzing the data that I overlooked?
 

bugman

Super Moderator
#2
I think you are confusing levels and factors.
This to me looks like a two way ANOVA:

2 factors: Ethinicity and Emotion expression with 2 and 6 levels respectivley. Y=response time.

The model looks fine and should be easy to interpret. Run your overall test then look at pariwise comaprisons - if this is part of the design.

Phil
 
#4
number of subjects

How do you know how many subjects you will need to conduct a rigorous experiment with a 2 X 6 factorial design?
 

bugman

Super Moderator
#5
Look at previous studies in the area for an idea of how much variation you can expect and conduct pilot studies.

Money will often be the deciding factor.
 
#6
Haha, thanks
This is an actual homework question I have, that for the life of me I cannot find anything about in my textbook. It states:

For a 2 X 6 factorial design . . . .
How many independent variables are there? (my answer) 2

How many dependent variables are there? (my answer) 1 if it's an ANOVA

*Approximately how many subjects will you need to conduct a rigorous experiment?* (my answer)I have no clue!