Sampling methods (3.2)

Question 1

Common data collection methods

Answer 1

• video recordings
• audio recording
• in situ (on site) notes

Question 2

What is sampling?

Answer 2

Used whenever the observer cannot continuously code all the relevant
behaviors of all the subjects being studied

•You want the behaviors you record to be representative, so your inferences are
not biased, Reduces observer bias by using a systematic method for selecting what to observe and when

Question 3

What are sampling method considerations?

Answer 3

• Behavior based considerations
• Scheduling based considerations

Your decisions should be guided by your research question and your
constraints

Question 4

Events vs. States

Answer 4

•Behavioral events – instantaneous behaviors (or coded as such)
-Useful to code this way if your interest is in frequency of events
-If the events do last for an appreciable duration, operationalize when to 
count them (e.g., at onset? At offset?)

•Behavioral states – have an appreciable duration
-Useful to code this way if you want to know about durations or % of time
spent in an activity
-Typically record onset and offset

Question 5

What is data completeness?

Answer 5

•Partial

• Provides an unknown percentage of the total occurrences
• Varies from sample to sample and individual to individual
• Often the result of Ad Libitum sampling

•Complete
-Record every time the behavior occurs during your sampling time for the
subset of subjects you are observing
-Provides frequency information

•Record if the event did or did not occur during your sample session

Question 6

What are some commonly coded info?

Answer 6

•Date and time of session onset and offset
•The actors (targets) of the observation session
•The receivers of the actors’ behaviors
•The sequence of states or events
•The time of the states or events (can be used to determine
sequences)
•Duration of states (total time)
•Onset and offset times of behaviors of interest (can be used to
determine duration)

Question 7

When to start your samples?

Answer 7

•Time sampling
-Stratified random sampling – pick x number of samples within a time window
and randomly determine them (e.g, 3 random times every hour)
-Regularly scheduled intervals – e.g., the first thirty seconds every 5 minutes

•Event sampling
-Whenever the state or event occurs

•Ad libitum sampling
-No specified rules, take notes when observations of interest occur

Question 8

When to end sampling sessions?

Answer 8

• Fixed: guided by a rule
• Ad libitum: no clear cut sampling rules, more prone to bias, problematic for making inferences abt thing like frequency

Question 9

Who to observe?

Answer 9

•Focal individual (or sub-group): focal follow method
- Record the behaviors of interest of a particular individual during the entire
sampling period

Question 10

Who to focus on?

Answer 10

•Randomly determined
•Stratified random sample (e.g., randomly pick one male and one female)
•Systematically rotate through the individuals
•Irregular / based on a behavioral criterion (e.g., first pair to interact, or the closest one in
view)

Question 11

Sampling Methods

Answer 11

• Continuous record
• Ad libitum
• Time sampling
• Event sampling