Laboratory experiments have higher internal validity but lower external validity. Fixed design vs flexible design. In a fixed research design the subjects, timing and location are established before data collection begins, whereas in a flexible design these aspects can develop throughout the data collection process. There are different types of interviews, often differentiated according to their level of structure. Structured interviews involve predetermined questions asked in a predetermined order. Unstructured interviews are more fluid. Semi-structured interviews fall in between. Interviews are commonly used in market research, social science and so in this guide we will outline all the elements of a good research proposal and explain why they are important. The elements of a good research proposal are title, introduction, literature review, goals and objectives, methodology, research scope, outline and timetable, and bibliography. It is important to include them. Examples of literature reviews · Search for relevant literature · Evaluate and select sources · Identify themes, debates, and gaps · Outline the structure of the literature review · Write your literature review: Explain your methodological approach: Describe your collection methods data: Describe your analysis method: Evaluate and justify the methodological choices you have made. Tips for writing an effective methodological chapter. Other interesting articles.