2. • Developmental research designs
examines the phenomenon with
reference to time.
• This design is generally used as
adjunct research designs with other
research designs such as cross-
sectional-descriptive, longitudinal-
correlational research design.
7. • The value of the longitudinal
design is in its ability to
demonstrate change over a
period of time.
• Longitudinal studies are
classified into three types :
TREND STUDIES, PANEL STUDIES,
FOLLOW-UP STUDIES.
8. TREND STUDIES
• Trend studies aims at
investigating a sample from a
general population over a time
with respect to some
phenomenon.
9. • Trend studies permit researchers
to examine pattern and rate of
changes and to make prediction
about future direction based on
previously identified patterns
and rates of changes.
10. PANEL STUDIES
• A sample of people involves in
the study are referred to as a
panel.
11. • In panel studies, same people are
involved and over a period of time
because they become more
informative on the phenomenon
than the subjects in trend studies
because ue the researcher cannot
only examine the patterns of
change, but also reasons for
change.
12. • The same selected people are
contacted for two or more times
to collect further data.
13. FOLLOW - UP STUDIES
• Follow-up studies are
undertaken to determine the
subsequent states of subjects
with a specified condition or
those who have received a
specific intervention.