In 1994 the decomposition of calciumoxalate monohydrate as a three-step reaction has been investigated by 13 labs using the TG-method. The authors working group performed objective kinetic evaluations of 144 TG data sets obtained from the same charge of substance in different laboratories. A non-linear optimization procedure was applied for different reaction models to perform single and overall optimizations. The results were analyzed critically on the basis of real model concepts for the course of the dehydration, the CO-split off and of the CO2-split off respectively. The results allow an optimistic assessment for the application of kinetic procedures to solid state reactions with well-known chemical course investigated by TG.