Animals perform a continuous stream of behavior throughout their lives. Because their
behavior is not random, appropriate sampling methods can be used to obtain data that
accurately reflect the actual behavior and are valid for answering research questions.
Answering questions related to several variables assists in narrowing the choices
of sampling methods. First, a determination must be made of what behaviors to measure.
If the behaviors are few and easily measured, then All Occurrences Sampling is the
method of choice because it generates accurate frequency and duration data through
continuous recording. Sequence and Sociometric Matrix Sampling are specialized types
of All Occurrences Sampling that are restricted to sampling intra- or interindividual
sequences and social interactions (e.g., agonistic), respectively. Second, if who
(e.g., specific individual, sex, or genotype) performs the behavior is a major component
of the research question, then consideration should be given to Focal Animal (Pair,
Group) Sampling. Third, if when or where the behavior is performed is of interest
(e.g., activity budget), then Instantaneous or Scan Sampling can often be effective.
Ad libitum Sampling does not produce valid data for analyses, but it is useful when
formulating and fine-tuning research questions. One-Zero Sampling is not recommended
except when the research question relates to the presence or absence of behaviors
only. Other factors to consider in selecting a sampling method are duration of the
behavior (event or state), desired scale of measurement (nominal, ordinal, interval,
or ratio), and logistics (e.g., time, and equipment and facilities available).