After the transition to secondary school around age 12, a well-known decline in young adolescents' motivation for learning causes particular concerns in the lowest level of secondary education, where the percentage of early school leavers is highest. This article focuses on a study of the effects of an intervention, designed to enhance motivation of students who are at the start of the lowest level of secondary school. An earlier intervention was further developed and tested with a random selection of students from classes in pre-vocational education by varying the components of the interventions in order to find possible effects of specific components or of the order of the two assignments of the intervention. Results showed positive effects of the intervention on students' investment in schoolwork.