These observations led us to assume that prompting students to provide multiple solutions
can foster their performance. However, the design of the TIMSS video study did not allow
causal inferences to be made about the effects of this teaching element. The first aim of the
current study was to clarify the benefits of prompting and constructing multiple solutions
compared to instructional settings in which only one solution has to be developed, using a
randomised pretest-instruction-posttest design. The second aim was that we wanted to understand
how the assumed positive effects of multiple solutions on performance come about, that
is, what motivational and cognitive variables mediate the effects of prompting multiple
solutions on students’ performance. In the current paper, we addressed these two research
aims using demanding modelling problems.