This study shows that formative methods and increased student participation has a positive influence on learning measured as grades. The study was conducted during the course Biology A in a Swedish Upper Secondary School. The students constructed grade criteria and defined working methods and type of examination within a given topic, Gene technology. The procedure resulted in variation within teaching and examination carried out as an oral test in small groups. In the analysis, students' grades on Gene technology were analysed in comparison with grades on other topics within the course, and the results show that mean grade is significantly higher on Gene technology. Based on the results and student course evaluations, I discuss the reasons behind the good results and the relation to participation, student interest, teacher and type of examination.