Listed below is the whole range of research designs that you could use for your dissertation.
Historical Research Design - The purpose is to collect, verify, synthesize evidence to establish facts that defend or refute your hypothesis. It uses primary sources, secondary sources, and lots of qualitative data sources such as logs, diaries, official records, reports, etc. The limitation is that the sources must be both authentic and valid.
Case and Field Research Design - Also called ethnographic research, it uses direct observation to give a complete snapshot of a case that is being studied. It is useful when not much is known about a phenomenon. Uses few subjects.
Descriptive or Survey Research Design - It attempts to describe and explain conditions of the present by using many subjects and questionnaires to fully describe a phenomenon. Survey research design /survey methodology is one of the most popular for dissertation research. There are many advantages.
Correlational or Prospective Research Design - It attempts to explore relationships to make predictions. It uses one set of subjects with two or more variables for each.
Causal Comparative or Ex Post Facto Research Design - This research design attempts to explore cause and affect relationships where causes already exist and cannot be manipulated. It uses what already exists and looks backward to explain why.
Developmental or Time Series Research Design - Data are collected at certain points in time going forward. There is an emphasis on time patterns and longitudinal growth or change.
Experimental Research Design - This design is most appropriate in controlled settings such as laboratories. The design assumes random assignment of subjects and random assignment to groups (E and C). It attempts to explore cause and affect relationships where causes can be manipulated to produce different kinds of effects. Because of the requirement of random assignment, this design can be difficult to execute in the real world (non laboratory) setting.
Quasi Experimental Research Design - This research design approximates the experimental design but does not have a control group. There is more error possible in the results.
Return from research designs to design and dissertation methodology.