According to Baltimore Public County Schools, limitations include factors the experimenter cannot control, while delimitations are boundaries the experimenter intentionally sets. Both affect methodology and research data.
With limitations an experimenter considers time constraints, nature of the experiment, instruments utilized and the sample itself. Delimitations set the boundaries of what the experimenter will not be studying and the procedures not being utilized, including reasons for both. Baltimore Public County Schools notes that certain limitations can distort qualitative research if the experimenter wishes to make inferences about a population.
According to Central Washington University, limitations and delimitations cannot be blocked, but only minimized, suggesting that researchers maintain honesty when conducting experiments. Examples of limitations include needing to use a translator because the experimental subjects speak a foreign language or relying on written response data rather than meeting the subjects.
In addition, Northern Arizona University relate limitations and delimitations to internal and external validity. Internal validity refers to the credibility and believability of the research data in the context of instrumentation construction. When researchers attempt to reduce the effect of a given limitation, it is called mitigating a threat to internal validity. External validity, or generalizability, relates delimitations to issues regarding whom, when and where. Northern Arizona University continues by adding that for an experiment to have a high internal validity, it must make a trade-off and give up some external validity.