Page 39 - Balancing between the present and the past

items). World orientation is a combination of history and geography multiple-choice
items and forms a substantial part of the test. The history items focus on content
knowledge and historical reasoning competencies. For example, students have to
date historical pictures and choose periods in which there was war in the Netherlands 2 (Dutch National Institute for Educational Measurement, 2013).
2.4.3 Data analysis
To answer the first two research questions, we began by examining the psychometric quality of the Nazi Party instrument and the slavery instrument. To be able to do this, we needed a coding system. In contrast with Hartmann and Hasselhorn (2008), who worked with latent class analysis, we used student mean scores on both instruments. Hartmann and Hasselhorn (2008) conducted their research on a small and homogeneous population. In our study, working with student mean scores showed the best results regarding the large and heterogeneous research population.
The present-oriented perspective items of both instruments used the following coding system from left to right for the answer columns (see Appendix A and Appendix B for the four columns). Selecting the first column yielded 4 points, the second column 3 points, the third column 2 points, and the last column 1 point. The role of the historical agent and historical contextualization items had the opposite coding system from left to right. Selecting the first column yielded one point, the second column two points, the third column three points, and the last column four points. A mean category score was calculated by summing the category items’ scores and dividing this score by three (because each category has three items). A total mean score of HPT was calculated by adding up the different mean category scores and dividing this score by three (because the instrument has three categories).
To test the content validity of both instruments, we asked 10 teachers from the teacher network of the Department of Teacher Education of the University of Groningen as an expert panel. The results of two teachers were deleted due to procedural mistakes when conducting the assignment. The eight teachers varied in work experience from 2 to more than 30 years. We also asked 10 historians who held a position at a university or at a university of applied sciences as a second expert panel. Because they are accustomed to taking historical perspectives, they ought to score consistently high on the role of the historical agent and historical contextualization items and low on the present-oriented perspective items. All historians held university degrees in the
Measuring historical contextualization
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