Imagine you are a a principal of a middle school and would like to have reliable teacher evaluation method. Thus, you had teachers submit evidence for their teaching effectiveness.

a. One teacher provided the evidence that 60% of her students received grades of a B or higher at the end of the school year. As a person who have learned experiment or design, you think this is a very weak design. Explain why this is a weak design.

b. According to the designs listed in your textbook, what type of experimental design is this? It is Quasi-Experimental Design. Also depict the design process using the notations such as R, X, O, explain this design.

c. As a principal, you would like to suggest a better research design for this teacher. What would you suggest to reduce the external threat of the study? Justify your answer.