I am attempting to investigate 7891 students who recently took an undergraduate entrance exams. I am interested in estimating this econometric model (i.e. Logit/Probit) to investigate factors affecting the result of students who took the exam. The results status has three factors, i.e., unsuccessful, regular pass and provisional pass. I have attempted in coding the three factors as binary. That is, I assigned "1" for both regular and provisional pass as "Passed"; and "0" for unsuccessful as "Failed". Please comment on this coding. Another thing is that, I estimated both probit and logit models taking my y binary variable on average test scores (mathscores+englishscores)/2) plus gender plus other categorical variables, but I get error message as highly collinearity for the average test score. I really need the variable as my key predictor variable, but it is not working. Can I ignore or drop it and use the raw scores for english and math separately in my models? Your views and references are highly needed. Thanks! Joe