Descriptive studies, sometimes
called observational studies, are done to identify or clarify characteristics
of specific populations. Questionnaires, interviews, and surveys
are often used for this purpose. Knowing characteristics of a population
can aid in the prediction of potential problems in that population
as well as the development of intervention strategies. When two
or more groups (cohorts) are sampled in a descriptive study, data
can be compared to determine similarities and differences.
Examples of variables examined
in such research include attitudes, opinions, beliefs, and/or eating
habits. Relationships between variables can be determined to determine
associations or a lack thereof.
A survey can be administered
once (cross-sectional) or repeated over time (longitudinal). Survey
research is limited by the subject's willingness to report information
(and report it accurately), and by response rate. Often, 100% of
those surveyed do not respond to a given survey, which can bias
the results if there is a difference in attitude or behaviors of
the respondents and nonrespondents.
Descriptive studies can be
considered a type of epidemiological research.