This chapter discusses research methodology in adult development and aging psychology. It explains that adult development psychology uses the same methodologies as other areas of psychology, such as experiments, correlational studies, and surveys. Some challenges to research in this field include finding adequate control groups, generalizing results, and measuring change over time longitudinally. The chapter also outlines different research designs used in adult development psychology like cross-sectional, longitudinal, and sequential designs.

1. National University
College of Letters and
Sciences
Research Methodology in Adult Development and Aging
Steven Mendoza, Ph.D.,MSCP
Psychology Adjunct Professor
March 2015

2. Chapter 5 Research Methodology in Adult
Development and Aging.
• The Psychology of adult development is a branch
of scientific psychology, and thus shares the
methodological concerns of the parent field.
• Adult development psychology uses the same
kinds of data, generated by the same procedures,
as do other fields of psychology.
• The formal experiment, the correlational study,
the use of survey methodology are as much in
evidence here as elsewhere.

3. Chapter 5
• As is true for other areas of psychology,
researchers in this field often have trouble
finding an adequate control group, to which to
compare their experimental group---
• ---they have problems generalizing their results
beyond the particular individuals whom they
happened to observe, and they worry about
statistical distortions.

4. Chapter 5
• Cross sectional designs compare several age
groups (Cohorts) at the same time.
• They yield data on age differences.
• Longitudinal designs compare the same cohort at
different times. They yield data on age
changes….

5. Chapter 5
• There also are additional concerns, not always
faced in other branches of psychology, that relate
directly to the fact that in the developmental
sciences we not only describe static phenomenon.
• But most importantly are concerned with the
measurement of change over time. Finally, there
are special methodological problems in doing
research with older subjects.

6. Chapter 5
• Longitudinal studies suffer from subjects loss,
practice effects, and historical changes that
affect behavior.
• But, cross sectional studies are more prone to
confusion of age effects with differences between
generations (Cohorts).

7. Chapter 5
• Cross sectional cont’d:
• Difference scores tend to be less reliable than
scores on single occasions; alternate methods,
require three, or more measurement points.

8. Chapter 5
• A major research problem in adult development
is finding representative samples; white, middle-
class males are generally overrepresented in the
research literature.
• but in advanced old age woman are
overrepresented in the research literature.

9. Chapter 5
• Longitudinal studies also have the problem of
keeping the sample representative once it is
recruited; lower-class subjects, for example,
tend to drop out in disproportionate numbers.
• Sequential designs are complex combinations of
the simple cross-sectional, and longitudinal
designs.
• A cross-sectional consists of two, or more cross-
sectional studies run at different times.

10. Chapter 5
• A longitudinal sequence consists of concurrent
longitudinal studies of two, or more cohorts.
• Schaie’s most efficient design includes both cross
sectional, and longitudinal sequence.
• Formed by retesting the subjects of an earlier
cross-sectional study while testing new subjects
in a new cross-sectional study.

11. Chapter 5
• Analysis of the resulting data can be cohort-
sequential (cohort v. Age), cross-sequential
(cohort v. time of measurement).
• In repeated measures design the same subject
are tested at different times.
• Independent samples designs test new subjects
from the same cohort, instead of re-testing the
same subjects at different times.

12. Chapter 5
• Many experiment Designs (quasi experiments)
may yield important insights and allow
researchers to examine alternative explanations
for a variety of aging phenomena.
• Age-comparative experiments compare groups of
subject of different ages to assess their
performance of some behavior in order to
determine if a particular factor explains the age
differences in behavior.

13. Chapter 5
• Single age group intervention designs study a
group on whom longitudinal data is available, and
compare the effects of intervention on stable
individuals experiencing decline.
• Molar equivalence-molecular decomposition
experiments seek to discover how the older
person might compensate for declines in
performance in one area by enhance
performance in another area.

14. Chapter 5
• In addition to concerns about reliability , validity,
and objectivity, several issues bear on the validity
of developmental research.
• Relationships between observables, such as test
performance and behavior, and latent constructs,
such as anxiety and intelligence, must be stable
across time to provide valid representation of
performance.

15. Chapter 5
• The method of confirmatory factor analysis is
used to test the equivalence of these
relationships across time, or different age groups.
• The generalizability of research finding must also
be taken in to account.

16. Chapter 5
• The extent to which research findings can be
broadly applied depends greatly on the
representativeness of the sample.
• It is also necessary to be aware of the
demographics, and health characteristics of
subjects in order to understand how finding
may be relevant to other populations.