Overview of Psych Methods
Survey Methods
Single-Case Designs and Small n Research
Repeated Measures Designs
Introduction to Complex Designs
Experiments vs Non-Experiments
Threats to Internal Validity
Scientific Method
Complex Design
Review Questions
Cafe Scientifique

Sampling Behavior

n    The extent to which observations may be generalized (external validity) depends on how behavior is sampled.

n    Two methods are time sampling and situation sampling.

n   Researchers typically use a combination of both methods.

n   The goal of both methods is to obtain a representative sample of behavior.

Sampling Behavior (continued)

n    Time Sampling: Researchers choose time intervals for making observations.

n   Systematic: Schedule observations to occur at a regular time (e.g., first day of the week, each noon).

n   Random: Use some random means for identifying times for observations.

n   Time sampling is not used when researchers wish to observe rare events (e.g., behavior following a hurricane).

n   Event sampling is used for rare events (for example, the researcher travels to the site of a recent hurricane).

Sampling Behavior, continued

n    Situation Sampling: Researchers choose different settings, circumstances, and conditions for their observations.


n   Situation sampling enhances the external validity of findings.

n   Within situations, researchers may use subject sampling to observe some people in the setting (e.g., choose every 5th person to enter a store).

Classification of Observational Methods

n    Two categories of observational methods:

n  Observation without Intervention

n  Observation with Intervention


n    Observational methods can also be classified according to the methods for recording behavior.

n  Comprehensive record of behavior

n  Selected behaviors

Observation without Intervention

n    Naturalistic Observation: Observation in natural (“real-world”) settings without an attempt to intervene or change the situation.

n   Goals: Describe behavior as it normally occurs, examine relationships among naturally occurring variables.

n   Naturalistic observation helps to establish the external validity of laboratory findings.

n   Naturalistic observation is used when ethical and moral considerations prevent experimental manipulation.

Observation with Intervention

n    Most psychological research involves observation with intervention.

n    Researchers typically choose from three methods of observation with intervention in natural settings:

n  Participant observation

n  Structured observation

n  Field experiment

Observation with Intervention (continued)

n    Participant Observation: Observer is an active participant in the natural setting he or she observes.

n   undisguised: people in the setting know they are being observed

n   disguised: people don’t know they are being observed


n    Disguised participant observation helps control for reactivity, one of the main problems associated with observation.


n    Reactivity occurs when people change their usual behavior because they know they are being observed.


n    Participant observers may sometimes lose their objectivity by becoming too involved in the situation.


n    Participant observers may influence the behavior of people they are observing.


Observation with Intervention (continued)

n    Structured Observation: Researcher sets up (structures) a specific situation in order to observe people’s behavior.

n    Examples: clinical and developmental observations of behavior, psychological testing

n    Structured observation is useful when behavior is difficult to observe as it naturally occurs.

n    Researchers often use confederates to create the structured situation.

n    Problems occur when observers don’t follow the same procedures across observations or observers, and when important variables are not controlled.


n    Field Experiment: Researcher manipulates an independent variable in a natural setting and observes behavior (dependent variable).


n   There must be two or more conditions to compare (independent variable).

n   Researchers often use confederates to create these different conditions.

n   Researchers attempt to have the most control in field experiments.


Recording Behavior


n    Researchers can obtain a comprehensive record of people’s behavior (e.g., video tapes) or select specific behaviors to record.


n    The method for recording behavior determines how the results of the study are eventually measured, summarized, analyzed, and reported.


n    Qualitative Records

n   Researchers use narrative records when they want a complete (comprehensive) reproduction of people’s behavior.

n  Examples: videotapes, audiotapes, field notes

n   Narrative records should be made during or soon after behavior is observed.

n   Observers must be carefully trained.

n   Advantage: Can review the record often to observe behavior.

n   Disadvantage: Costly, time-consuming.


n    Quantitative Records

n   Selected Behaviors: Researchers choose the behavior they want to observe and ignore other behaviors.

n   Researchers need to decide how they will measure the behavior.

n  Examples: frequency of behavior, duration

n   Recording techniques include checklists and electronic recording and tracking.


Analyzing Observational Data

n    Reliability: Reliability refers to consistency.

n    We need to know whether two or more observers agree (are consistent) in their observations.

n    This is called interobserver reliability.

n    Factors that affect interobserver reliability:

n   characteristics of the observers

bored, amount of experience, looking at different things (what you and I consider to be “effective” may differ)

Researchers need to train their observers and provide feedback about errors and discrepancies.

n   events and behaviors to be observed and recorded are not clearly defined

The researcher needs to be clear to both observers as to what she means by “effective.”

It’s best to provide examples.

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