In order to improve the work with data and the understanding of random phenomena in teaching of probability, it is essential to know the ideas students bring from their everyday lives. These ideas largely influence their way of understanding the material discussed.
Therefore, in my research I focused on the intuitive understanding of basic concepts in describing random phenomena. I constructed a questionnaire that was given to 107 university students.
Based on their answers, I tried to find out what their initial perceptions of concepts such as probability, chance, and mean are. The survey revealed that pupils' ideas about basic mathematical concepts differ significantly from those of teachers.