Russel-Research-Method-in-Anthropology

The Foundations of Social Research 53
Validity, Reliability, Accuracy, and Precision
Validity refers to the accuracy and trustworthiness of instruments, data, and
findings in research. Nothing in research is more important than validity.
The Validity of Instruments and Data
Are the instruments that were used to measure something valid? Are SAT
and GRE scores, for example, valid instruments for measuring the ability of
students to get good grades? If they are, then are grades a valid measure of
how smart students are?
Is the question ‘‘Do you practice polytheistic fetishism?’’ a valid instrument
for measuring religious practices? No, it isn’t, because the concept of ‘‘polytheistic
fetishism’’ is something that is meaningful only to specialists in the
comparative study of religion. Asking people that question is asking them to
think in categories that are alien to their culture.
Is the instrument ‘‘How long does it take you to drive to work each day?’’
a valid one for measuring the amount of time it takes people to drive to work
each day? Well, that depends on how accurate you want the data to be. If you
want the data to be accurate to within, say, 20 minutes on, say 70% of occasions,
then the instrument is probably valid. If you want the data to be accurate
to, say, within 5 minutes on, say, 90% of occasions, then the instrument is
probably not valid because people just can’t dredge up the information you
want at that level of accuracy.
The validity of data is tied to the validity of instruments. If questions asking
people to recall their behavior are not valid instruments for tapping into informants’
past behavior, then the data retrieved by those instruments are not
valid, either.
The Validity of Findings
Assuming, however, that the instruments and data are valid, we can ask
whether the findings and conclusions derived from the data are valid. Asian
Americans generally get higher scores on the math part of the SATs (scholastic
aptitude tests) than do other ethnic groups in the United States. Suppose
that the SAT math test is a valid instrument for measuring the general math
ability of 18 year olds in the United States. Is it valid to conclude that ‘‘Asians
are better at math’’ than other people are? No, it isn’t. That conclusion can
only be reached by invoking an unfounded, racist assumption about the influence
of certain genes—particularly genes responsible for epicanthic eye
folds—on the ability of people to do math.