Hello, and welcome to Science Buddies!
When doing an experiment, it is never too early to think about data collection and analysis. I do statistical analysis and deal with this problem on a weekly basis. If you don't think about data collection and analysis during your research phase, you could design the perfect experiment with no feasible means to collect a/o analyze data. I've seen it happen!
You are correct that you won't have the actual data; but before you start your experiment, you should have a data collection and analysis plan. This plan (and what you can turn in Monday) should consist of:
1. What data are you planning to collect? This should be data tied to your dependent variable that will help you test your hypothesis.
2. What methods will you use to collect the data? Are you using instruments, a questionnaire, ???
3. How will you analyze the data? For example, are you comparing averages of something? If there are mathematical equations involved, it never hurts to include them in terms of your experiment.
4. How do you intend on presenting your data? Graphs, data tables, ??? After all, collecting a lot of data is useless unless you can present the results in a way that people can understand.
As you go through this process, you may find difficulties in collecting and/or analyzing your data. In that case, you will need to modify your experiment. The purpose of submitting your plan now is to ensure you have thought through this and ensure your experiment is doable before you potentially waste time, money, and effort for nothing.
I hope this helps. Be sure to write back with additional questions.