Psychology:

Research methods - Observational study in lab setting

How can the observational methodology be analysed

• Video - Repeated view accurately inter+Intra observation validity

• To observe all actions of the infant

• Infants can’t self report

A weakness of the observational method?

The interference of demand characteristics would show heavy bias

Social desirability will compel mother to speak highly of their infant to maybe seem normal

Demand characteristics will cause the participants, mother specifically to give what the researcher wants.

Information on Lab experiments

Experiment takes place in a carefully controlled environment e.g lab, classroom 

Strengths

High internal validity due to control of extraneous variables

Easily replicated so demonstrates external validity

Limitations

Participants know they are being studied - lacks ecological validity (realness!)

Lack of mundane realism

Potential for demand characteristics

Example: Milgram’s’ study of obedience

Information on Field experiments

Takes place in a more natural setting - IV is still manipulated by investigator

Strengths

Participants not usually aware they are being studied - reduces demand characteristics (but potential ethical issues)

More realistic - higher ecological validity and mundane realism (not guaranteed)

Limitations

Harder to control extraneous variables reducing internal validity

More time consuming

Example: Piliavan et al Bystander effect (subway samaritan)

Information on Natural experiment

Naturally occuring IV (not manipulated by experimenter) typically linked to the environment. DV can still be measured in a lab or field setting 

Strengths

Enables study of ‘real life’ problems/situations

Allows research on an IV that couldn’t otherwise be studied

Limitations

Can’t demonstrate cause and effect easily as IV not directly manipulated

Can’t control for confounding variables as participants not randomly allocated to groups

Limited opportunities to use and v hard to generalise to other people

Example: Charlton et al intro of TV on St Helena Island and influence on behaviour

Information on Quassi experiment

Still a naturally occurring IV based on an internal characteristic e.g. male vs female  

Strengths

Allows comparisons between different groups of people

Limitations

Can’t establish cause and effect (lack of control of confounding variables)

Example: 

Sheridan and King (1972) - impact on gender on obedience through giving electric shocks to puppies!