This paper is proposing a reflexion on statistical modeling of tests scores. It is questionning the real differences that one could observe between "Classical test theory" and "Item response theory". It maintains that these two views of testing are useful for classification and prediction of those who take large-scale tests, but little useful for diagnosis of examinees’ problems. It ends by suggesting that more fruitfull ways of seeing the problem are getting more and more attention. These promising approaches try to merge test theories and findings in cognitive psychology and focus their attention on process rather than solely on results.