The intervention consisted of two approaches. In Approach 1, the PSTs were required to solve three problems; describe in detail narrative form the processes they went through in solving them; develop a model of problem solving based on the processes; share and discuss their processes and models in small groups; develop a group model of problem solving and represent it as a flow chart. In Approach 2, they were required to solve three different problems and describe their solution processes by recording every time they were stuck and got an idea (an Aha!); develop a model of problem solving; share and discuss their processes and models in small groups; develop a group model of problem solving and represent it as a flow chart.