You can use various types of questions, depending on how much scaffolding you want to give, to collect lab reports from students. A short answer question allows for more open response. A totally open response would be to give an essay type and have them enter the entire report in one question. The more specific the question in terms of answers available, the more scaffolded the question. E.g. For primary students, we may have them experiment with colour, and when they mix red and blue, we expect purple. We could give them multiple choice, even without words and only colour pictures where they need to identify their results.