This project addresses the transition of Luxembourgish students from primary to secondary school. Inparticular, we investigate (1) the cognitive processes of teachers which determine the choice of the futureschool type and (2) the prognostic validity of teachers’ transition decisions.The transition decision sets up a social ecology that can either promote or hinder a student’s academicgoal attainment and is therefore of particular importance. However, the decision is frequentlypredominated by the social background of the student (socioeconomic status, migration status), anddifferences between students get even more pronounced after the transition depending on the selectedschool type.Though biases in teachers’ judgments are well documented, little research has addressed the underlyingcognitive processes which may cause erraneous decisions. Social cognition research has providedelaborated theories of biases in cognitive processes and constitutes therefore our conceptual framework.Accordingly, we conceptualize the decision as the result of a cognitive process including attention,storage, and retrieval of information about a student, and socioeconomic and migration status as socialstereotypes which direct information processing toward selective attention to and retrieval ofstereotypical information.According to our research goals, the project consists of two complementing research lines. To analyze theprognostic validity, we are tracking the progress of all sixth-graders across this transition into thefollowing three school years in a school monitoring project which is currently set up in cooperation withthe Luxembourgish Ministry of Education. The types of information which will be considered are (1)teachers’ transition decision, (2) social background of the student, (3) 6th grade marks and those of thefollowing three years and (4) teachers’ informal assessments of students. According to our theoreticalframework, we analyze the relative importance of each type of information for the decision and therelationship between the decision and students’ school career.The second line of research conceptualizes the cognitive processes underlying the transition decision andis experimental in nature. Teachers of a sample drawn randomly from the school monitoring projectreceive vignettes of students which include the same types of information as the school monitoringproject, but social background information and 6th grade achievements are experimentally varied. In threeseries of experiments, participants’ task is to read the information provided by the vignette, to selectinformation cueing the transition judgment, and to decide upon an appropriate secondary school. The useof elaborated research techniques from cognitive psychology (“Eye-tracking”, “Mouse-lab” technology,“Think aloud” method) allows to determine which type(s) of information predominantly attract attentionas an indicator of importance and are retrieved from memory during the judgment process and howretrieved cues are combined into a decision.Our methodological approach allows to relate the experimental results to the corresponding findings ofthe school monitoring study for every single participant. As a consequence, the external validity of ourexperimental results may be assessed and, vice versa, the formation of the transition decision in themonitoring study may be causally explained. Ultimately, we aim at further elaborating our theoreticalframework and at developing intervention strategies based on our findings.This project is embedded into a research agenda funded by the FNR (Grant FNR/06/09/18 given toRomain Martin) and the DFG (Grants KR2162/3-1 and KR2162/4-1 given to Sabine Krolak-Schwerdt),and may offer the opportunity to orchestrate our research into an innovative account of educationalachievement judgments.