1. The case is a description of the actual situation. In this case, there are one or more problems, and there may be solutions to these problems.

2. "Teaching cases describe teaching practice. In a rich narrative form, some stories including typical behaviors, thoughts and feelings of teachers and students are shown to people. "

3. Teaching cases refer to teaching situation stories containing some decisions or problems, which reflect the typical level of teaching thinking and its maintenance, decline or achievement. The collection of such cases must be done well in the field in advance, and relevant materials should be consciously selected from the objectives of teaching task analysis. Here, the researcher's own insight is the key.

4. Teaching cases refer to "narrative teaching practice records written jointly by teachers or researchers and teachers."