Page 135 - Getting the Picture Modeling and Simulation in Secondary Computer Science Education

Students’ Understanding and Difficulties
6.3.4 Data Analysis
We performed a qualitative analysis of the interviews and of the documentation students turned in. We first identified text segments of documentation and interview transcripts in which model validity played a role. The units of analysis were coherent chunks of text pertaining to a specific action related to aspect contributing to determining validity, and reasoning behind it.
In the first analysis phase, the text segments were classified according to the core categories in our validation process model (see Figure 13):
• Construct the model through reasoning (by the modelers themselves)
• Test the model (by the modelers themselves)
• Discuss the model (with others)
• Reflect
In the second phase, we analyzed the strategies employed by the students
within each category by means of an open coding process. In subsequent coding cycles, we grouped the descriptions of the students’ validation activities into more abstract descriptive categories, using the elements of our validation process model (see white ovals in Figure 13) whenever possible.
In the third phase we looked for students’ difficulties and misconceptions
within each of the resulting categories and classified them in a similar open coding
process. 6
In the process of determining the coding schemes for strategies and difficulties, the first and second author analyzed parts of the interviews separately and discussed their findings until they agreed on the classification.
6.4 Results
In this section, we portray the activities the students reported employing in order to develop validated models while constructing and testing their models, and while reflecting. We use our theoretical framework depicted in figure 13 to organize the presentation of the results. We state our findings in general terms and illustrate them with characteristic text segments taken from the data.
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