(^112) Johns Hopkins Nursing Evidence-Based Practice: Model and Guidelines, Third Edition
Table 6.3 Descriptive Designs and Purpose
Title Definition/Purpose Notes
Univariate descriptive
studies
Explain the frequency of a
behavior or an occurrence.
Questionnaires, surveys.
Descriptive
comparative designs
List differences between two
or more groups on one or
more independent variables to
find out why the variables are
different.
Groups that are similar in some
but differ in other respects; the
differences become the focus
of examination.
Descriptive
correlational designs
Describe relationships among
variables by statistical analysis.
As one relationship varies, the
other varies in the same or
opposite direction; does not
determine whether one variable
causes another.
Prevalence studies Determine the proportion
of a population that has a
particular condition at a
specific point in time.
Useful to compare prevalence
of disease in different
populations or to examine
trends in disease severity over
time.
Incidence studies Determine the frequency (or
incidence rate) of new cases.
Useful in understanding risk for
disease development.
Predictive designs Predict future relationships or
outcomes based on patterns
within a set of variables.
Applies statistical methods and/
or data mining techniques,
without preconceived
theoretical constructs.
Example: Nonexperimental Predictive Correlational Design
Mazanec, Daly, Douglas, and Musil (2011) used a predictive correlational design
to examine the role of cognitive appraisal in predicting post-radiation treatment
psychological adjustment in women with various forms of cancer. The research
team prospectively examined the relationship between cognitive appraisal and
psychological adjustment (outcome variable).