Types of experiment

• Laboratory - Conducted in a controlled environment . They can manipulate the IV and minimise the EV
• Field - Behaviour is measured in a natural environment like a park . A key variable is still altered so the effect can be measured
• Natural - Studies variables that aren't directly manipulated by the experimenter
• Quasi - The researcher is not able to use random allocation to put participants in different conditions . Usually, the IV is unchangeable like gender or age
• Strengths of laboratory experiments are: it is in a controlled environment , replicated , controlled variables , can be repeated and effects of the EV can be minimised
• Strengths of field experiments are: high external validity , high internal validity , high ecological validity , less artificial than lab experiments and its more of a natural environment
• Strengths of natural experiments are: they are uncontrolled so can be more accurate and they are real life
• Strengths of quasi experiments are: the researcher cannot interfere
• Weaknesses of laboratory experiments are: they are artificial , not representative of real life , and cannot be generalised , they are expensive and participants may respond to what they think is being investigated
• Weaknesses of field experiments are: researcher has less control and the participants do not agree to take part
• Weaknesses of natural experiments are: they are not random, they are not controlled, they are not generalisable and the conditions cannot be changed
• Weaknesses of quasi experiments are: Participants may not be representative of the target population , the researcher may not be able to control all extraneous variables and the ethical side can be difficult to obtained