Russel-Research-Method-in-Anthropology

602 Chapter 20
ference in productivity in Harshbarger’s sample, no matter where they got
credit, or even if they didn’t use credit.
Carole Jenkins (1981) surveyed 750 children in Belize for protein-calorie
malnutrition (PCM). She had four means—one for each of the four ethnic
groups (Creole, Mestizo, Black Carib, and Maya) in her research area. An
analysis of variance showed that there was a very strong relationship between
ethnic group and the likelihood of suffering from childhood PCM.
Sokolovsky et al. (1978) compared the average number of first-order relations
and the average number of multiplex relations among three groups of
psychiatric patients who were released to live in a hotel in midtown New York
City. (First-order relations are primary relations with others; multiplex relations
contain more than one kind of content, such as relations based on visiting
and on borrowing money from, for example.)
One group of patients had a history of schizophrenia with residual symptoms;
a second group had a history of schizophrenia without residual symptoms;
and the third group had no psychotic history. An ANOVA showed
clearly that the average network size (both first-order and multiplex networks)
was different among the three groups. From these data (and from field observation
and in-depth interviews), Sokolovsky was able to draw strong conclusions
about the ability of members of the three groups to cope with deinstitutionalization.
Whenever you observe three or more groups (age cohorts, members of different
cultures or ethnic groups, people from different communities) and count
anything (e.g., some behavior over a specific period of time, or the number of
particular kinds of contacts they make, or the number of kilograms of fish they
catch), then ANOVA is the analytic method of choice. If you are interested in
the causes of morbidity, for example, you could collect data on the number of
sick days among people in various social groups over a given period of time.
Other dependent variables in which anthropologists are interested, and which
are amenable to ANOVA, are things like blood pressure, number of minutes
per day spent in various activities, number of grams of nutrients consumed per
day, and scores on tests of knowledge about various cultural domains (plants,
animals, diseases), to name just a few.
When there is one dependent variable (such as a test score) and one independent
variable (a single intervention like the reading program), then no matter
how many groups or tests are involved, a one-way ANOVA is needed. If
more than one independent variable is involved (say, several competing new
housing programs, and several socioeconomic backgrounds), and there is a
single dependent variable (a reading test score), then multiple-way ANOVA,
or MANOVA, is called for. When two or more dependent variables are corre-