Health Care and Research Substruction in

What is Substruction,Components of Substruction,Conceptual Framework,Process of Substruction,Series of Question related to Substruction Process.

What is Substruction

    Substruction is a heuristic technique, designed to be helpful in
planning research and critiquing published research. It was first introduced to
the nursing research literature by Hinshaw (1979). She outlined four steps in
the process of substruction: 

(1) identify and isolate major concepts

(2)
specify relationships among the concepts

(3) hierarchically order concepts by
level of abstraction

(4) pictorially present relationships among the
variables. 

Components of Substruction

    She provided guidelines for conducting theoretical substruction.Substruction now comprises two components. The theoretical system
explicates the relationship between constructs and concepts through
articulating postulates or statements of relationships. 

    For example, the
construct of quality of life might postulate that it is composed of three
dimensions or concepts, including physical, social, and spiritual. Thus, there
is an implicit level of abstraction in substruction, moving vertically down
from the most abstract (constructs) to fewer abstract notions (concepts). 

    It is
true that in the English language some authors will consider the words
constructs and concepts to be interchangeable, and this must be recognized as a
potential source of confusion when discussing substruction. The labels are less
important than the idea of levels of abstraction.

Conceptual Framework

    In addition to examining vertical, conceptual relationships, the
theoretical system examines across constructs through articulating axioms and
propositions. Axioms are statements linking constructs; propositions are
statements of relationships between or among concepts. 

    For example, an
investigator may hypothesize the relationship between the concepts of severity
of illness and quality of life. The study might state as an axiom that there is
an inverse, predictable relationship between severity of illness and quality of
life. An author might hypothesize that as illness becomes more severe, the
quality of life diminishes.

    The authors may conceptualize the severity of illness to have
related concepts, just as the construct quality of life had three concepts.
Perhaps the severity of illness is conceptualized to have two concepts,
including physiological status and severity of symptoms.

    If one is reading or planning an intervention study, the construct
may be the intervention itself, such as patient teaching. There may also be
concepts related to the intervention, such as type of delivery technique (group
vs. individual) or time spent on teaching activity as a measure of dose of the
treatment. 

    Each of these concepts may be operationalized in the operational
system as strategies to assess the take of the treatment, even though the
treatment may have as its empirical indicator Yes or No or “received
treatment” or “did not receive treatment.”

Process of Substruction

    The operational system was added by Dulock and Holzemer (1991) in
their article on the process of substruction. The operational system requires
the investigator to link each concept identified in the theoretical
substruction with an empirical indicator or measure. 

    The process of identifying
the measures for each concept (or sub-concept) highlights for the reader how
the investigator operationalized the constructs. Sometimes this process reveals
that, although an investigator included a construct or concept, the variable
was never actually measured in the study.

    This process of identifying the empirical indicators or measures
also helps the investigator to give attention to the validity and reliability
of each measure selected to ensure confidence in the results of the
measurement. 

    Finally, a review of the empirical indicators assists with an
analysis of the level of scaling of the measures so that the reader can have
confidence that an appropriate statistical analysis was conducted. 

    Labeling the
scores obtained from empirical indicators or measures as continuous or discrete
leads one directly to the discussion of parametric or nonparametric analyzes
and which approach might be appropriate. 

Series of Question related to Substruction Process

    Dulock and Holzemer (1991) outlined a
series of questions that can be generated related to the process of
substruction when either planning or critiquing research studies. These
questions have been modified and included the following:

1. What is the evidence that supports the relationships between
constructs and concepts in the study?

2. What is the evidence that supports the relationships between
constructs and concepts?

3. How does the study propose to measure each of the identified
concepts?

4. Is there evidence of the validity and reliability of the
measures?

5. What level of measurement will result from these instruments?

6. Are the data analysis techniques appropriate for these measures?

7. Is there a logical consistency between the theoretical system
and the operational system?

    They wrote: “These questions are designed to guide the exploration
of the relationships between the theoretical and operational aspects of a
study. The analytical process of subtracting helps one to focus upon the study
as a gestalt of interrelationships” (p. 86). 

    Substruction has proved to be an
extremely useful tool when developing a new research project as well as for
analyzing published studies. As a heuristic technique, substruction helps the
researcher to understand how to think about the relationships among the
selected variables or to understand how the author conceptualized these
relationships.