The limitations and delimitations sections of your research proposal describe situations and circumstances that may affect or restrict your methods and analysis of research data.

Limitations are influences that the researcher cannot control. They are the shortcomings, conditions or influences that cannot be controlled by the researcher that place restrictions on your methodology and conclusions. Any limitations that might influence the results should be mentioned.

When considering what limitations there might be in your investigation, be thorough. Consider all of the following:

your analysis.
the nature of self-reporting.
the instruments you utilized.
the sample.
time constraints.
In qualitative research certain limitations might mean that the findings cannot be generalized to the larger population. This is especially true when the definition of the population is broad (ex: elderly women)

Delimitations are choices made by the researcher which should be mentioned. They describe the boundaries that you have set for the study. This is the place to explain:

the things that you are not doing (and why you have chosen not to do them).
the literature you will not review (and why not).
the population you are not studying (and why not).
the methodological procedures you will not use (and why you will not use them).
Limit your delimitations to the things that a reader might reasonably expect you to do but that you, for clearly explained reasons, have decided not to do.

Delimitations define the parameters of the investigation. In educational research the delimitations will frequently deal with such items as population/sample, treatment(s), setting, and instrumentation.