Wallin, AnitaAndersson, Björn2009-01-272009-01-272005http://hdl.handle.net/2077/19217The overall purpose of our research is to study how students develop understanding of scientific theories, in this study the theory of biological evolution by natural selection. Taking students' preconceptions as the starting point a teaching–learning sequence has been designed, implemented and assessed in a cyclic process. During one trial a group of 18 students (grade 11) was studied using various methods. Just after the theory was introduced, an interactive database-driven Internet problem was used for formative assessment. It deals with the evolution of the length of legs in a population of reindeer and consists of seven parts. The student is at first asked to speculate about the evolution of the length of legs, given a description of its variation. Then more and more information about the actual change in the length of legs and environmental circumstances is presented. The students are offered the possibility of changing their previous answer, as they work through the problem. Already in the opening part of the problem, 16 students answered with scientific evolutionary ideas. Our hypothesis is that if the intraspecific variation is explicitly given, it promotes evolutionary reasoning. The students appreciated the problem, and considered it as an opportunity of learning.engconference paper, peer reviewed