Table 2 Training phase example comments for the different self-explanation prompts conditions

At the beginning, the tutor tried to collect and then organize the students' naïve preconceptions about blood. This is important because the teacher should pick up on the everyday ideas of the students.^a One student then also associated Dracula with blood, but the tutor did not go into this further. The tutor then asked how blood is pumped through the body. Here the different students described different procedures. Most of the students described it as being pumped into the arm, back to the heart and then on to the leg, and so forth. Only one girl said that she thought it was a cycle because it was called a blood cycle. The tutor then worked with this statement to provoke a conflict among the other students. The girl then said that there must be two cycles. One upper and one lower. The lower one flows into the two arms. Then the tutor wanted to know whether or not the legs needed oxygen. Again, he wanted to provoke a conflict in the girl’s thinking, since that can't be. He then explained to her that it is just one cycle and how it works. In the end, he wanted to check whether she understood and modified her knowledge but this was not the case. She did not understand it! He wanted to come back to it later on. What I noticed was that while he was discussing with the girl, he was only talking to the girl and did not include the other children, even though they also had no real idea about the blood circulation. [not scored because the strategy was not part of the PCK introductory text]^b. The other students attended to other things during this time

T does not elicit students’ misconceptions^c: The tutor has the students speak about their ideas but does not respond to them, he does not provide relatable examples [incorrect]

T evokes cognitive conflict: He responds to the girl’s idea and clarifies that her idea is not fully correct [incorrect use of the “cognitive conflict” button]

T elicits students’ misconceptions: He has the students explain their ideas (voluntarily)

T provides scientific alternatives: The tutor tries to correct the girl’s misconception. However, he only responds to her and ignores the other students [incorrect use of the “providing alternatives” button]

T checks for modifications: The tutor asks the girl to once again demonstrate how the blood circulates (which she can’t)

T does not evoke cognitive conflict: The other students don’t listen to the conversation between the tutor and the girl [incorrect use of the “cognitive conflict” button]

T does not check for modifications: He only checked the girl on the right but he did not check for modifications in the other students’ understanding