• Control over dependent variables and the conditions for applying the experimental variable.
• Precision in measuring the dependent and independent variables
• Provides rigorous tests of causal hypothesis
• High internal validity
• Easy to conduct, lowcost

• Possible difficulty in creating experimental and control groups
• Low external validity (difficulty in generalizing results)

Quasi-experiments

• High on external validity
• Can be conducted in natural settings
• Can approach but not equal the strengths of experiments

• Low on internal validity
• Difficulty of obtaining equivalent experimental and control groups

Surveys

• Simultaneous measurement of numerous variables at one time
• Can provide multiple measurement of the same indicator, closed and open-ended items can be used in the same instrument
• Collection of data from large samples
• Provides descriptive information for a large number of variables
• Data can be statistically analyzed
• Allows for generalization in populations

• Time consuming, can be expensive
• Limited level of measurement of variables
• Provides limited understanding of why relationships occur
• Potential for reactivity
• Possible bias in constructing the questionnaire
• Possible bias in interviewing
• Difficulty in detecting inaccurate or false responses

• Non-reactive
• Can be done at the convenience of the researcher
• Specific data can be used - dates, frequencies, qualitative data
• Broad coverage, far more than a single investigator could collect
• Provides data for trend studies
• Little or no cost involved

• Bias during collection of data unknown
• Data may be poor or invalid measures of concepts on wants to measure
• May be difficult to access

Causal observation

• Focus on events as they happen
• Non-reactive
• See events in their natural social context
• Easily repeated for verification
• Excellent for exploring a topic

• Only a limited number of variables that can be observed at one time
• Potential bias on the part of the observer in observing, recording observations, analyzing and interpreting data
• Limited to observation of small groups in specific social setting
• Limited value for generalizing (based on small groups, relatively few observations)

• Focus on real-life processes and events
• Descriptions of events in their natural social context

• Time consuming, lengthy process
• Requires high level of skill and experience
• Potentially reactive