For every scientific concept there are likely to be a number of alternative procedures available for observing, or operationalizing, the relevant phenomena. For example, the concept strength of electrical current can be operationalized in measurements of heat change, intensity of light, electrical shock felt by a person, changes in speed of a motor, changes in magnetic fields, and so forth. The same idea applies in anthropology, and it is often useful to employ more than one measure or mode of observation in the study of particular cultural institutions. This is the principle of multi-instrument research. The anthropological fieldworker, therefore, must have a number of different research tools in his or her field kit. Unlike the situation in the laboratory sciences, research tools in anthropology involve relatively little in the way of hardware and gadgetry but require great sensitivity and self-awareness on the part of the investigator. The fieldworker is the principal research instrument, and the various methods of investigation are alternative techniques for objectifying and standardizing the fieldworker's perceptions.

The research tools to be discussed in this chapter and the following one are the most frequently encountered techniques of anthropological investigation. It is not a complete inventory, however, and every fieldworker should be constantly alert to the possibilities of developing new modes of observation to supplement the standard items. Usually, new field-work techniques are refinements or modifications of one or the other of these main techniques.