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I am struggling to interpret the results of a binomial logistic regression I did. The experiment has 4 conditions, in each condition all participants receive different version of treatment. DVs (1 per condition)=DE01,DE02,DE03,DE04, all binary (1 - participants take a spec. decision, 0 - don't)
Predictors: FTFinal (continuous, a freedom threat scale)
SRFinal (continuous, situational reactance scale)
TRFinal (continuous, trait reactance scale)
SVO_Type(binary, egoists=1, altruists=0)
After running the binomial (logit) models, I ended up with the following:see output. Initially I tested 2 models per condition, when condition 2 (DE02 as a DV) got my attention. In model(3)There are two variables, which are significant predictors of DE02 (taking a decision or not) - FTFinal and SVO Type. In context, the values for model (3) would mean that all else equal, being an Egoist (SVO_Type 1) decreases the (log)likelihood of taking a decision in comparison to being an altruist. Also, higher scores on FTFinal(freedom threat) increase the likelihood of taking the decision. So far so good. Removing SVO_Type from the regression (model 4) made the FTFinal coefficient non-significant. Removing FTFinal from the model does not change the significance of SVO_Type.

So I figured:ok, mediaiton, perhaps, or moderation. I tried all models both in R and SPSS, and entering an interaction term SVO_Type*FTFinal makes !all variables in model(2) non-significant. I followed this "http: //www.nrhpsych.com/mediation/logmed.html" mediation procedure for logistic regression, but found no mediation. (sorry for link, not allowd to post more than 2, remove space after http:)

To sum up:

Predicting DE02 from SVO_Type only is not significant.
Predicting DE02 from FTFinal is not significant
Putitng those two in the regression makes them significant predictors

code and summaries here

Including an interaction between these both in a model makes all coefficients insignificant.
So I am at a total loss: As far as I know, to test moderation, you need an interaction term. This term is between a categorical var (SVO_Type) and the continuous one(FTFinal), perhaps that goes wrong? And to test mediation outside SPSS, I tried the "mediate" package (sorry I am a noob, so I am allowed max 3 links per post), only to discover that there is a "treatment" argument in the funciton, which is to be the treatment variable (exp Vs cntrl). I don't have such, all ppns are subjected to different versions of the same treatment. Any help will be appreciated.

Yavor Paunov
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    Please post a [reproducible](http://stackoverflow.com/questions/5963269/how-to-make-a-great-r-reproducible-example) question. – user2100721 Aug 11 '16 at 13:16
  • Dear user2100721, I cannot link more than 2 items with my reputation. The dataset is here: http://www.filedropper.com/final_24

    And the code here: http://www.filedropper.com/stack_1     – Yavor Paunov Aug 11 '16 at 14:00
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    This doesn't seem like a question about programming at all. It seems like a question about statistical model fitting. If that's the case, such questions belong on [stats.se], not Stack Overflow. But the question still really needs a reproducible example in the question itself. Don't link to data externally because those links will often break in the future. The question should be self contained. – MrFlick Aug 11 '16 at 14:18
  • I would recommend to move to Cross Validated, and post the model (as formula). You seem to be doing a straightforward logit, can you boil it down to two models that reflect the problem? – Ott Toomet Aug 11 '16 at 18:35
  • Hi, I moved the post to Cross Validated, if you guys wanna follow up. Should I remove it from here, or it is better to link it? – Yavor Paunov Aug 12 '16 at 09:50

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