Sampling in Research

Your school and three others in your area have noticed that teaching evaluations have consistently gone done over time. How would you select a sample of students that would allow you to investigate the cause of the problem and begin to craft a strategy to turn the situation around?
(You can select either quantitative (eg. random sampling, strata sampling, etc.) or qualitative sampling (eg. convenience sampling, snowball sampling, etc.)
(strategy)
Using the sample devised above, explore the data collection method (s) that you would utilize and why, to obtain valid and reliable data and information for analyzing the problem and devising the response strategy.
(Please note that your data collection methods should align with the sampling strategy and therefore the appropriate methodology, i.e., quantitative or qualitative, * should you decide to use mixed methods, then you will need to have both sampling methods used and indicated)
Main Response is 500 words with responses.
Remember to use established evidence to support statements and points and provide a reference list.