Process Coding – Heuristics: Appearances of heuristic techniques (like drawing a
figure or examining special cases) were coded using a manual that was designed on the
basis of a framework by Koichu, Berman, and Moore (2007) (cf. Rott 2012 for details).
Similar to the episodes, the videos were coded independently by several researchers
with interrater-reliability PA > 0.7 for identifying points of time in the processes with
heuristics and PA > 0.85 for characterizing the heuristics. After calculating the
reliability, we attained agreement by recoding together all differing codes.