# Should I use a randomized block design?

In my study, we investigated the effect of sex and location on fish length taken from 3 different regions: A,B, C. From each site we randomly took 10 females and 10 males. Now I am going to test whether sex and/or region affect fish length. I am not really sure which method should I take to analyse my data. 2 way ANOVA with randomized block design? Please guide me on this.

  A       B       C
50.1    53.4    54.0
52.8    55.2    49.1
50.8    51.0    60.5
58.8    59.3    57.8
59.7    61.5    48.7
49.0    61.2    57.0
58.8    57.8    61.1
62.2    50.1    62.8
57.8    56.0    59.8
61.2    56.5    60.3
Female
46.5    57.5    49.1
44.4    59.3    51.8
42.0    62.4    55.3
51.1    61.1    43.6
45.8    59.9    50.1
46.3    55.6    51.0
41.8    56.8    49.0
52.0    59.2    48.8
46.5    50.4    52.0
39.0    47.8    43.0

• It looks like you have 2 factors of interest and no subplots, so a CRD makes sense. Is there some other variable you want to block on? Ideally, this would all be decided prior to running the experiment. – Joel Mar 3 '17 at 15:35
• My supervisor asked me to test whether sex and/or region affect fish lenght. He did not say anything about a nuisance factor!! I just assume that region might be. I dont know what I should do – Non Mar 3 '17 at 16:13

• +1 makes sense, although the OP did say investigated the effect of sex and location on ... Perhaps that's not actually what they intended. – Joel Mar 3 '17 at 15:56