*External validity: the extent to which findings may be generalized.
GENERALIZING TO OTHER POPULATIONS OF RESEARCH PARTICIPANTS
COLLEGE STUDENTS (and rats)
o The potential problem is that such studies use a highly restricted population.
o The student population tend to young and posses the characteristics of late adolescence a
sense of self identity that is still developing, social and political attitudes that are in a state of
flux, a high need for peer approval and unstable peer relationships.
o Students are most similar to each other than adults are similar to other adults.
o How are college students like lab rats they are easy to obtain
o External validity may be limited because the data obtained from volunteers may be different
from what would be obtained with a more general sample
o Volunteers differ in many ways from the non volunteers more educated, higher
socioeconomic status, more social.
o And the title of the study does influence who signs up.
o Important implications for external validity
The use of Internet is still more common in a particular demographic.
And on top of that finding the volunteers.
o Gender bias may arise in psychological research, including confounding gender with age or job
status and selecting response measures that are gender stereotypes.
o The location that participants are recruited from can also have an effect
o Participants from one local may differ from participants from a different local.
o Thus, study conducted at one location may not generalize to participants at a different location
GENERALIZATION AS A STATISTICAL INTERACTION
o An interaction occurs when a relationship between variables exists under one condition but
not under another or when the nature of the relationship is different in one condition than in
IN DEFENSE OF COLLEGE STUDENTS (and rats)
o Criticisms of the use of any particular type of subject, such as college students, should be
backed with good reasons that a relationship would not be found with other types of subjects.
o Replication of the research studies provides a safeguard against the limited external validity
o The value of studying rats has been demonstrated by research that applies findings to humans
People say that psychology is built on the study of WEIRD people (Western, educated, industrialized,
rich and democratic)
Comparisons: western cultures are individualistic and eastern cultures are collectivist
Social support styles are different in both the cultures.
Similarities: low waist to hip ratio is attractive in all cultures.
GENERALIZING TO OTHER EXPERIMENTERS
The person who conducts the experiment is source of external validity too
Some important characteristics: the experimenter’s personality, gender and experience
A warm friendly experimenter might y