I have the following setting (& would like to pick a model/or transformation that can help): dv is normally distributed continuous variable, all IVs are continuous, but one of them is the above mentioned variable which has values between 0 and 1, having two spikes at 0 and 1. In between there is a normal-like distribution (though slightly skewed and quite flat). What can I do with this variable? Ln(Y) or Ln(Y+c) or other transformation (tried inverse trig, inverse, sqrt)? Is there a nice model? Non-parametric? Dummies? Multiple tests?
Help appreciated, a beginner in statistics