In this research two different ways of students' reviewing their knowledge in chemistry about carbohydrates are described: group work and discussion with teacher. In experimental group (EG) students were working in groups on their assignments, while in control group (CG) discussion led by teacher was implemented. Results showed better EG students’ achievements on paper-and-pencil test of knowledge on the following class. Keywords: evaluation, group work, teacher-led discussion, carbohydrates.