Experimental Methods Flashcards
What are the four types of experimental methods?
-Laboratory
-Field
-Natural
-Quasi
what is a laboratory experiment?
-experiment carried out in a controlled setting, allowing researcher to exert a high-level of control over the IV and eliminate control for cofounding variables
-IV manipulated to observe effect on DV, highly controlled
What are strengths of laboratory experiments?
-Control over variables shows causing effect to be established (IV caused by DV)
-Replicability as possible, which means reliability can be established (control)
what are limitations of laboratory experiments?
-artificial conditions make it difficult to generalise other settings, lacks ecological validity (caused by control, due to task)
-Demand characteristics can occur as participants respond to cues of the aim experiment
What is a field experiment?
-an experiment carried out in the natural environment of the individuals being studied
-IV- directly manipulated by experimental to observe effect on DV.
-The participant may not know that they are being studied
-Some control
What are the strengths of field experiments?
-improved ecological validity because pp’s are unaware they are taking part and in a natural environment
-Reduction of demand characteristics Because the participants are unaware they are taking part in an experiment
What are the limitations of field experiments?
-less control of extraneous variables
-More time-consuming, as you need to wait for environmental conditions
What is a natural experiment?
-IV isn’t directly manipulated
-IV occurs naturally
-allocation of participants not controlled by experimenter
what are strengths of a natural experiment?
-Reduction in demand characteristics
-high ecological validity due to lack of direct intervention
what are limitations of natural experiments?
-inevitable many extraneous variables because of a lack of control
-replication is impossible due to rarity of the situation
what is a quasi experiment?
-has an IV that is based on existing difference between people (predetermined characteristics- planned)
-No one has manipulated this difference, it simply exists
What are strength of quasi experiments?
-often carefully planned, which makes it replicable
-useful to make comparison between types of people where it is impossible or impractical to manipulate variables
What are limitations of quasi-experiments?
-Can’t randomly allocate participants to conditions, and therefore there may be confounding variables, which means we cannot establish causality
-Often carried out in a laboratory, and therefore may be demand characteristics
What is an example of a lab experiment?
Asch’s variations
what is an example of a field experiment?
bickman
