- RESEARCH DESIGN AND STATS
Types of Research
The purpose of this section is to present an overview of
the types of research designs most commonly utilized in the
rehabilitation and medical sciences. As consumers of research
literature, it is important that life care planners are equipped
to critique journal articles and to determine whether study
findings are relevant to the patients with whom we are working.
Recommendations in the life care plan must be supported by
research data and based upon the documented course of disability
and patient-specific variables over time.
The manner in which a researcher designs a study determines
the type and depth of information which can be concluded
from the project. For this reason, researchers spend a significant
amount of time considering the most effective design in addressing
the topic of interest. First, a researcher determines the
purpose of the study. Are they seeking to:
*Explore or describe a research problem? Then
surveys, case studies, and developmental studies may be most
*Explain or predict relationships between variables? Then
relational, associational, correlational, or ex post facto
designs may be most effective.
*Control, establish cause and effect, or induce
a result? Then experimental or quasi-experimental
are likely to yield the most useful results.
Descriptive research designs are most effectively applied
to studies aimed at gathering additional information, learning
more about an area of interest, or becoming more familiar
with a topic. Researchers interested in identifying the prevalence
or incidence of a disability or in describing the distribution
and characteristics of a group of patients may adopt a descriptive
The purpose of conducting survey research is to explore
and/or describe an area of interest in greater detail. Typically,
a researcher gathers information from a large group of participants
either by mail, interactive online site, telephone interview,
or personal interview.
Results from this type of study will produce a “snapshot” of
the current state of the research issue. A survey does not
investigate relationships between variables, patient-specific
characteristics, or generalize findings to all members of
a population. In other words, the purpose of survey research
is not to establish cause and effect relationships. Most
individuals have completed a survey of some type, whether
a public opinion questionnaire, customer service form, or
community investment poll.
Developmental studies generally follow a group of participants
over time and document changes in status. These types of
studies may be referred to as trend, cohort, or panel designs.
In most cases, researchers collect data at specific points
in time which are used as a basis of comparison and analysis.
Narrative or documentary-style reports may result from this
type of design, but conclusions cannot be applied to other
members of the target population. Developmental studies are
useful in describing phenomena longitudinally and may be
used as the foundation for further investigation.
Case Study or Qualitative Designs
The purpose of this type of research is the same as pursued
by survey and developmental designs, but generally involves
much smaller sample sizes. Rather than gathering information
from a large group of people, as in survey designs, the researcher
is interested in gaining deeper insights into a fewer number
of subjects. This form of inquiry typically involves personal
interview or direct observation throughout the data collection
process. Examples of this type of design may be a study based
on the relationships and interpersonal dynamics of a specific
family, documenting the experiences of a small group of patients
with traumatic brain injury in a rehabilitation facility,
or observing the interactions of selected toddlers in a preschool
Relational or Associational Research
The purpose of relational or associational research is to
identify the relationship or association between two or more
Correlational studies are appropriate when comparing two
or more characteristics within the same group of participants
(Ary, Jacobs, & Razavieh, 1999). The purpose is not to
establish cause and effect but to:
*demonstrate how specific characteristics vary together,
*assess the degree to which one characteristic can be predicted
when another is known.
There are two types of correlational studies; concurrent
and predictive. Concurrent correlational studies involve
assessment of the relationship between characteristics that
were collected by the researcher at the same point in time.
For example, a researcher may be interested in assessing
the relationship between patients’ emotional well-being
and levels of impairment when beginning a vocational rehabilitation
Predictive correlational studies may be utilized when a
researcher is interested in determining whether knowing a
previously documented characteristic (or set of characteristics)
can lead to the prediction of a later characteristic (or
set of characteristics). For example, a researcher may record
patients’ emotional well-being when beginning a vocational
rehabilitation program and then again after 60 days of job
placement to ascertain whether earlier data was predictive
of later data.
Ex Post Facto Studies
Ex post facto, or “after the fact” designs,
attempt to identify a natural impetus for specific outcomes
without actually manipulating the independent variable. This
type of design is often utilized when it is not possible
to control the experience, exposure, or influences which
may affect participants.
Experimental or Quasi-Experimental Research
The purpose of experimental or quasi-experimental research
is to establish a cause and effect relationship between two
variables. The researcher deliberately manipulates a treatment
(or independent variable) and measures how it affects the
behavior or reaction of subjects (the dependent variable).
In order for this research design to be appropriately utilized,
the researcher must be able to:
*randomly select subjects,
*randomly assign subjects to intervention and control groups,
*randomly assign treatment to intervention groups, and to
*control the treatment (or independent variable) and any
variables which may have an effect upon the dependent variable.
As may be apparent from the description, this type of design
is very difficult to utilize when working with human subjects.
Consider the ethical implications of withholding pharmaceutical
treatment from a control group in order to determine the
drug’s effectiveness. In order for the drug to be approved
for distribution to the general public, it is necessary to
establish its effectiveness. However, there exists the potential
for harm to individuals who participate in the project, whether
receiving the drug or not.
While this type of study occurs, and must occur if advances
are to be realized, there are many safeguards, supervisory
and administrative requirements, and limitations imposed
upon studies involving human subjects. For this reason, quasi-experimental
designs are commonly used in medical and allied health fields
* Note: Causality can only be established by true
experimental designs, so the term “cause” (or
derivatives) should not be used in association with any other
Quasi-experimental designs are used when the researcher
is unable to control for a necessary variable, or set of
variables, but follow stringent guidelines for controlling
error. For example, trials for an experimental pharmaceutical
may utilize a quasi-experimental design to ascertain the
effectiveness of a specific medication. Subjects are carefully
pre-tested and monitored as the independent variable (the
medication) is manipulated. Assuming that it was not possible
to randomly select or randomly assign subjects to treatment/control
groups, a quasi-experimental design (or pre-experimental
design) must be adopted.
Life care planners will analyze a variety of research data
when developing plans to meet patient-specific needs and
should be familiar with the basic assumptions and limitations
of each design. After reviewing several research articles,
discussing your thoughts with other professionals, and considering
the practical applications of various studies, you will gain
a level of comfort in evaluating research literature.
References for Further Reading
Ary, D., Jacobs, L., & Razavieh, A. (1999). Introduction
to research in education. Fort Worth, TX: Harcourt Brace
Bellini, J. & Rumrill, P. (1999). Research in rehabilitation
counseling: A guide to design, methodology, and utilization. Springfield,
IL: Charles C. Thomas.
Bolton, B. (1979). Rehabilitation counseling research.
Baltimore, MD: University Park Press.
Campbell, D., & Stanley, J. (1966). Experimental
and quasi-experimental designs for research. Skokie,
IL: Rand McNally.
Fowler, F. (1988). Survey research methods. Thousand
Oaks, CA: Sage Publications.
Kerlinger, F. (1986). Foundations ofbehavioral
research. New York: Holt, Rinehart, and Winston.
Kerlinger, F. (1973). Behavioral research: A conceptual
approach. New York: Holt, Rinehart, and Winston.
Spector, P. (1981). Research designs. Thousand
Oaks, CA: Sage Publications.
Trochim, W. (2001). The research methods knowledge base,
(2nd Ed.). Cincinnati, OH: Atomic Dog Publishing.