Research Methods
, Experiments
A research method in which an independent variable is manipulated to measure its effect on dependent
variable, which controlling the possible influence of other factors on the dependent variable
Simple Experiment Field Experiment
• Two conditions (control and experimental) • Usual manipulation of variables
• The most typical kind • Conducted in real-life environment
• Less control over external variables
Quasi-Experiment
• NO random assignment to the conditions Natural Experiment
• Participants are group based on pre-existing • Include pre-existing independent variables that
characteristics – they act as independent are manipulated naturally.
variables • Random assignment of participants is NOT
possible
CHARACTERISTICS
Manipulation of independent variables
• Exposing different participants to different conditions such as control and experimental
Measurement of dependent variables
• To record changes caused by manipulation of independent variable
Control over extraneous variables
• Limits the influence of extraneous variable on experimental results
• Helps to establish cause-effect relationship
Standardized procedure
• Ensures that procedure can be replicated
Research design
• Independent measures
• Repeated measure
• Matched pairs
Strengths Limitations
• Manipulation and control over variables • Could be unethical
→ Cause effect relationship • Isolation of external variables → artificial
• Standardized procedure → Replication → experiment → low external validity → low
validity ecological validity
• Control over variables allows to focus on • Participants might be fully aware that
one aspect of the study they are participating in a psychology
• Statistical analysis → organization and experiment → Reactivity effect
interpretation of data is easier • Participants might figure out the
hypothesis → Demand characteristics
• Reductionist
Field
• Can’t control confounding variables
• Can’t replicate it easily
Quasi and Natural
• Can only imply causal relationship.
Methods
, Experiments
A research method in which an independent variable is manipulated to measure its effect on dependent
variable, which controlling the possible influence of other factors on the dependent variable
Simple Experiment Field Experiment
• Two conditions (control and experimental) • Usual manipulation of variables
• The most typical kind • Conducted in real-life environment
• Less control over external variables
Quasi-Experiment
• NO random assignment to the conditions Natural Experiment
• Participants are group based on pre-existing • Include pre-existing independent variables that
characteristics – they act as independent are manipulated naturally.
variables • Random assignment of participants is NOT
possible
CHARACTERISTICS
Manipulation of independent variables
• Exposing different participants to different conditions such as control and experimental
Measurement of dependent variables
• To record changes caused by manipulation of independent variable
Control over extraneous variables
• Limits the influence of extraneous variable on experimental results
• Helps to establish cause-effect relationship
Standardized procedure
• Ensures that procedure can be replicated
Research design
• Independent measures
• Repeated measure
• Matched pairs
Strengths Limitations
• Manipulation and control over variables • Could be unethical
→ Cause effect relationship • Isolation of external variables → artificial
• Standardized procedure → Replication → experiment → low external validity → low
validity ecological validity
• Control over variables allows to focus on • Participants might be fully aware that
one aspect of the study they are participating in a psychology
• Statistical analysis → organization and experiment → Reactivity effect
interpretation of data is easier • Participants might figure out the
hypothesis → Demand characteristics
• Reductionist
Field
• Can’t control confounding variables
• Can’t replicate it easily
Quasi and Natural
• Can only imply causal relationship.
Methods
