Child Development

causal-comparative design offers little of the control
necessary to make cause-effect conclusions.

Longitudinal versus Cross-Sectional

Studies

By the very nature of their field of study, child de-
velopment researchers are concerned with change
that occurs over time. This fact brings to light another
research design choice that must be considered: lon-
gitudinal research versus cross-sectional research.
Longitudinal studies involve studying the same group
of participants over a particular time period. Cross-
sectional studies involved studying groups of partici-
pants in different age groups at the same point in
time. It would seem that longitudinal research would
be the developmental researcher’s first choice, but be-
cause of some of the disadvantages of that method,
developmental researchers must sometimes use the
cross-sectional method.

In a longitudinal study, a researcher performs re-
peated observations or testing at specified points dur-
ing the participants’ lives, thus allowing the
observation of development. The time span involved
may be anywhere from a few months to a lifetime.
This design provides the best information about the
continuity or discontinuity of behavior over time and
allows for the individual tracking of patterns of be-
havior, as well as trends of development, within a sim-
ilar group. The problems of this type of design can
often override the benefits. It is expensive to study a
large group of individuals over an extensive time
span. Keeping up with these individuals can be costly
and time consuming. Participants may move away
from home and local communities, and therefore
drop out of the study. Sometimes the participants be-
come wise to the testing or observations and practice
over repeated measures and contaminate the results.
Cohort effects may also be a factor in the outcomes of
longitudinal studies. Cohort effects are common
characteristics or trends in development for one co-
hort or group that may not follow suit for another co-
hort. To try to alleviate some of these potential
problems, researchers often study small groups of in-
dividuals; but this may make it difficult to generalize
the findings to a larger group.

Cross-sectional studies are quick by nature in that
a researcher does not have to follow the development
of each individual. At the same time a researcher does
not gain the rich data on individual development that
can be garnered from longitudinal studies, since the
evidence of change is inferred from differences be-
tween the age groups. The cross-sectional design is
also affected by the cohort effect where age differ-
ences may show trends particular to a specific group

and not true developmental changes. Thus, while the

cross-sectional design solves some the problems asso-

ciated with a longitudinal design (e.g., subject drop-

out and cost), the cross-sectional design still suffers

some disadvantages (e.g., age differences do not show

age change and cohort effects).

Summary

Qualitative and quantitative research methods

can be used in child development studies. The deci-

sion on which method to use is typically based on the

research question of interest and how researchers

have previously attempted to address the question.

With respect to qualitative methods, the researcher’s

job is to study the topic in its natural context with as

little intrusion as possible. In the quantitative meth-

od, the researcher’s job, after conceptualizing the

study, is to define the dependent and independent

variables or decide whether this kind of control is pos-

sible. In instances where variables cannot be con-

trolled, the researcher must use appropriate methods

to control for differences or use correlations to deter-

mine how the variables may be related to each other.

Using representative sampling is imperative to be

able to generalize the study to other populations and

settings. In either approach to child development re-

search, the ability to uncover interesting data and to

replicate it helps strengthen the field as a whole.

See also: THEORIES OF DEVELOPMENT

Bibliography

Graue, M. Elizabeth, and Daniel J. Walsh. Studying Children in Con-

text: Theories, Methods, and Ethics.Thousand Oaks, CA: Sage,

1998.

Isaksen, Judith Graver. Watching and Wondering: Observing and Re-

cording Child Development. Palo Alto, CA: Mayfield, 1986.

Lancy, David F. Studying Children and Schools: Qualitative Research

Traditions. Prospect Heights, IL: Waveland Press, 2001.

Vasta, Ross. Studying Children: An Introduction to Research Methods.

San Francisco: W. H. Freeman, 1979.

Terrill F. Saxon

Majka Woods Mitchell

MIDWIVES

A midwife is a person, usually a woman, who assists

other women in giving birth. Typically, this assistance

extends throughout pregnancy, labor, delivery, and

the newborn period. Midwives focus on delivering

healthy babies in as natural a manner as possible; they

also provide health counseling to mothers and fami-

lies. Although obstetricians and midwives have much

knowledge and experience in common, they occupy

different professions. While both are concerned with

MIDWIVES 271