Application of Behavior Change Theory to the Development

14
BEHAVIOR CHANGE THEORY
characteristics; researcher blinded to randomization schedule; and, temporality, the
evidence that treatment preceded outcome. The minimum and maximum possible
points ranged from 0 to 6. These points were then multiplied by a factor of four to
arrive at the final Design Quality score that ranged from 0 to 24. The factor of four was
established to emphasize that the design is the most important consideration in
research.
The quality of the treatment letters was determined from an assessment of the number
of TTM elements used in their construction, multiplied by a factor of three for the
general methods, a factor of two for the early stage techniques, and a factor of one for
the late stage components. The quality scores were allowed to range between 0 and 18,
0 and 10, and 0 and 5 for the general, early, and late stage elements, respectively.
Therefore, 33 would represent a perfect score across all 16 TTM components. The
general strategies were multiplied by three, the largest TTM factor, because the balance
of the methods used in the early and late stages of change will be less powerful in the
absence of the general strategies. The factor of two used to multiply the early stage
points reflects its relative importance to the general and late stage elements.
An evaluation sheet (Appendix A-1) was developed for the purpose of assessing each
study containing advisory treatment-letters or sufficiently detailed descriptions of
treatment contents. This evaluation sheet recorded the study’s title, author, source,
date, design characteristics scores, general strategy scores, early-stage strategy scores,
late-stage strategy scores, strength of association, and other factors relevant to the
evaluation. The evaluated studies were tabulated by the strength of evidence
supporting each treatment in terms of the quality of the research and the validity of the
methods as defined by the degree to which they reflected components of the
Transtheoretical Model of behavior change that was used as the assessment instrument.
Goal Attainment Scaling
Goal attainment scaling was also used in an attempt to define five levels of expectation
for each of the 16 TTM elements. Originally, it had been thought that this method
would provide a framework for an evaluation tool of sufficient sensitivity to distinguish
fine gradations of dissimilarity among the sentences used in the various letter
treatments to convey messages relevant to specific TTM change elements.
Goal Attainment Scaling (GAS) was developed in the 1960’s to address the especially
difficult evaluation needs within the mental health community (Kiresuk & Sherman,
1968). Since then, GAS has been applied to an expanding universe of fields including
education, social work, psychology, and even business (Kiresuk et al., 1994).
The technique requires desirable and undesirable outcomes to be documented in an
unambiguous manner through descriptive statements or quantitative data. Because
GAS is a dynamic concept, the goals and measurable outcomes defined can be subject to
continuous review and assessment to ensure that changing circumstances are not
neglected.