Negative attitudes and perceptions on programming impair the effectiveness of learning programming skills. In this study the attitude related to programming, problem solving, and self-views on importance of IT/programming knowledge were assessed by pre- and post-test completed at the beginning and at the end of a software development course. The study was conducted using an online questionnaire and four different dimensions were measured by a survey consisting 23 items. The results show positive moderate associations between self-commitment in problem solving and algorithmic and problem solving ability and negative weak relationship with lack of self-confidence in programming. K-means algorithm showed that the students could be classified into two main groups stronger and weaker self-confidence in programming. In the case of both clusters, it was possible to achieve a positive change in attitudes related to programming. In the case of weaker self-confidence in programming, a greater change can be observed in the attitudes, which can be considered an important result from the point of view of the effectiveness of the software development course. The research presented in the article proves that attitudes related to programming can be influenced in a positive direction both in the case of those with stronger, but even more so in the case of those with weaker attitudes.