The Testing Algorithmic and Application Skills (TAaAS) project was launched in the 2011/2012 academic year to test first year students of Informatics, focusing on their algorithmic skills in traditional and non-traditional programming environments, and on the transference of their knowledge of Informatics from secondary to tertiary education. The results of the tests clearly show that students start their studies in Informatics with underdeveloped algorithmic skills, only a very few of them reaching the level of extended abstract. To find reasons for these figures we have analyzed the students' problem solving approaches. It was found that the students, almost exclusively, only consider traditional programming environments appropriate for developing computational thinking, algorithmic skills. Furthermore, they do not apply concept and algorithmic based methods in non-traditional computer related activities, and as such, mainly carry out ineffective surface approach methods, as practiced in primary and secondary education. This would explain the gap between the expectations of tertiary education, the students' results in the school leaving exams, and their overestimation of their knowledge, all of which lead to the extremely high attrition rates in Informatics.