Page 201 - Encyclopedia of Nursing Research

168 n EXPLORATORY STUDiES

subjects to treatment and control conditions. the researcher has tried to cope with the vari-
Random selection is the process of randomly ous potential threats to each type of validity.
E drawing research subjects from the popu-
lation about which the researcher wants to Ivo Abraham
gain knowledge and to which the researcher Karen MacDonald
hopes to generalize the findings of a study.
Random assignment entails allocating
sampling units (e.g., patients) to treatment
and control conditions by using a decision Exploratory stuDiEs
method that is known to be random (e.g., coin
toss, random drawing, use of random tables,
computer-generated random sequences of Exploratory studies are those that investigate
options). For long, random selection was vir- little-known phenomena for which a literary
tually nonexistent in intervention studies in or experiential search fails to reveal any signif-
nursing; moreover, a large proportion (55.3%) icant examples of prior research. Exploratory
of nursing intervention studies did not even studies are useful in nursing research in find-
use random assignment methods (Abraham, ing out more about the nature of a nursing-
Chalifoux, & Evers, 1992). This is changing related problem or issue, and there usually is
with the growing emphasis on randomized a small sample that focuses on one particular
controlled trials of nursing interventions. area of interest or on one or two variables. The
in their classic text, Cook and Campbell kinds of research questions typically gener-
(1979) reviewed four types of validity of ated for exploratory studies are descriptive in
research designs, potential threats to each, nature and seek understanding (e.g., What is
and strategies to remedy these threats. it like to be a pregnant teenager? Who needs
Statistical conclusion validity addresses the home care? What health-promoting behav-
extent to which, at the mathematical/statis- iors do cafeteria workers engage in? What is
tical level, covariation is present between the lived experience of military widows and
the independent and dependent variables widowers?).
(i.e., the extent to which a relationship exists Because the intent of exploratory
between the independent and dependent research is to find out and explore unknown
variables). internal validity refers to whether phenomena, it is considered Level 1 research
an observed relationship between variables (designed to elicit descriptions of a single
is indeed causal or, in the absence of a rela- topic or population) and is reflected by many
tionship, that indeed there is no causal link. of the early research studies in nursing. An
Construct validity of putative causes and examination of early research designs used
effects refers to whether the causal relation- in nursing research includes the following:
ship between two variables is indeed “the (a) staff nurse behaviors and patient care
one” and tries to refute the possibility that a improvement (Gorham, 1962), (b) the self-
confounding variable may explain the pre- concept of children with hemophilia and
sumed causal relationship. External validity family stress (Garlinghouse & Sharp, 1968),
refers to the generalizability of an observed and (c) women’s beliefs about breast cancer
causal relationship “across alternate mea- and breast self-examination (Stillman, 1977).
sures of the cause and effect and across dif- Exploratory studies are still used in
ferent types of persons, settings, and times” nursing research and are often thought of
(Cook & Campbell, 1979, p. 37). Validity of as an initial step in the description of more
any type is not a yes/no issue of whether complex researchable problems or issues or
or not it is present. Rather, it is a matter of as part of mixed methods studies. However,
degree, determined by the extent to which exploratory studies are particularly useful