To gain insight into ideas and beliefs of students who finished an introductionary course on programming without any formal education on testing, we asked students to fill in a small questionnaire, to make four exercises in which they had to write test cases to decide whether a specific method is correct or not and to determine the correctness of a given implementation, and to fill in a second questionnaire. We interviewed eleven of these students, in a semi-structured interview, to obtain more in-depth insight. The main outcome of our research shows that students do not test systematically, while most of them think they do test sytematically. We found that many (of most) students can only think of test cases based on programming code. Even if no code was provided (black box testing), students try to come up with code to base their test cases up on. We found more misconceptions related to testing.