N.6 
Materialien aus der Bildungsforschung 
Eberhard Schröder 
Katja Bödeker 
Wolfgang Edelstein 
in collaboration with 
Thomas Teo, 
Julia Haasemann, and 
Manuela Timme 
The Development of Concrete Thought 
A Manual Including Measurement Procedures and 
Descriptive Analyses 
Study „Individual Development and Social Structure' 
Data Handbooks Part 1 
Berlin 2000 
Max-Planck-Institut für Bildungsforschung 
e 
Max Planck Institute for Human Der