Teacher retention / Principal Role

I have already begun the paper for this case study, however, I am uncertain how to answer three parts of the question:

• the constructs you will measure and what you will do in order to determine how to operationalize them (you need not identify specific measures)
• justification for why your chosen design and methods are more appropriate for your research question than alternatives you have considered
• your methods of data analysis
• the strengths and weaknesses of your envisioned design and methods

Please see below for more information on my study:
The purpose of this quantitative study is to examine the role that school leadership (principals) plays with regards to teacher retention in low – performing, Title I, non – white schools. The sample size will include both those students and principals employed with the El Paso Independent School District for a minimum of three years. The population will be limited to teachers and principals who have been employed in Title I, low – performing, non – white schools as it is within these that teacher turnover is among the highest. The population data will be collected from a database retrieved from the school district, updated monthly. This database will indicate the length of time teachers have been employed with the school district as well as their assignments.
After the principals and teachers with the required experience have been identified, each will be notified of the purpose of the study. Also, they will be informed that the survey is completely voluntary and there will be no repercussions for failure to complete the survey. However, if participants choose to contribute to the study there will be a prize drawing for a certain number of gift cards to encourage participation. The survey questions will be achieved from prior research articles as well as input from the school district. The survey questions will be on a scale from one to five, allowing the researcher to examine which elements are most important in both teacher career decisions as well as determine which practices principals that experienced principals use to achieve the greatest effect on teacher career decisions.