One of the major benefits of quantitative research is that the dissertation process tends to be very formulaic; you can set out your research hypotheses, decide on a suitable research strategy to collect data, using research methods that are highly standardized with pre-determined measures and fixed-options, and then analyse that data using tried and tested statistical tests, with the results from these tests directly answering your research hypotheses. As an undergraduate or master's students, this is a major advantage compared to dissertations that involve qualitative research.

During the data collection phase, you need to take advantage of this by making sure that you're well prepared. There are a number of areas to make sure that you are well prepared before you start collecting data, especially (a) the measurement procedure and (b) the sampling strategy you are using:

Overall, when it comes to the data collection phase of your research, be well prepared and stick to your research plan, but be ready to make changes if problems arise.