Solved – What’s the appropriate spss test

hypothesis testingspss

Context

I have 25 men and 25 women as participants, and they did exactly the same thing: Each of them
heard an attractive dialogue and they had to choose between a photo of a
woman in red and a woman in green. Then each of them heard an unattractive
dialogue and they chose again between the red and the green shirt.

My hypothesis is that men are attracted to women in red in contrast to women. So, I 've got gender (2levels:0=male, 1=female), attraction (1=yes, 0=no) and
trials/colour (0=green, 1=red)

I am interested in showing that the colour (red) predicts attraction as far as men
are concerned and that there are gender differences! Men are much more
attracted to it.

Questions

  • Should I use a test which combine all of them or a test that combine first
    the attraction and colour for men, then the attraction and colour for women
    and then the gender differences?

I've been told to run a pearson's correlation (one for men and one for women)
but I think that it demands interval data.I was also told to use the chi-
square test but it's not for participants who parrticipated in the same
experimental conditions.

  • What about repeated measures logistic regression?
    If so, can you give me some advice how to process my data? Any suggestions?

P.S. I really appreciate everyone who answered my previous posts
here and here, they helped me to go one step further!

Best Answer

If we can assume that the men and women were selected randomly, your design is a special case of completely randomized design (CRD) with 2 treatments. As you mention, repeated-measures, I must remark that if gender is assumed to be a block, then it models correlation (and repeated measures is a way of imposing correlation). If you treat gender as a block, then the design will be a randomized complete block design (RCB) with 1 treatment. You can still test the effects of gender, but the tests will be conservative.

In summary:

  • Response: attraction (0 or 1)
  • Treatment 1: gender (male or female)
  • Treatment 2: color (green or red)

If the analysis is CRD, then you model gender and color as fixed effects and attraction as response.

If the analysis is RCB, then you model gender as a block (random effect), color as fixed effect, and attraction as response.

Irrespective or RCB or CRD, your responses are binomial (Bernoulli, 0 or 1). Therefore the solition boils down to fitting a GLMM with a logit-link.

As you are interested in the relationship between men and color, you might want to include the interaction of color and gender in the model. This will be in the case of CRD. Once you have the model fit, you can use the following contrast to see if men are attracted to red than women:

$$H_0: g_mc_r-g_fc_r=0$$ $$H_a: g_mc_r-g_fc_r\neq0$$

Unfortunately, ANOVA (or GLMM) can't give you a one sided test, that is, $g_mc_r-g_fc_r>0$ (although I have seen people do it).

I am aware that SPSS can fit GLMM, but not sure how. I will let someone else give the exact SPSS instructions.

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