Perspective taking can be conceptualized in the framework of mental transformations in terms of subsequent egocentric transformations. Kozhevnikov and Hegarty’s (2001) PTSOT is a test instrument for adults that investigates double perspective taking processes. Both perspective taking processes can be defined by certain egocentric transformations. An adoption of this test for primary children reveals that they are able to understand the test and verbalize easily their thinking processes. 8 items were solved by 254 fourth graders. Results show a variety of typical difficulties that can be interpreted in detail using the egocentric transformations framework. The theoretical framework and the straightforward way of item construction allow us to systematically generate
items for various applications in psychology and mathematics education.