Types Of Experimental Methods Flashcards
What is an experiment
Studies in which the researchers investigate a cause and effect relationship by having one or more independent variables and measuring the effect of the independent variable on the dependent variable
Laboratory experiments
An experiment that takes place in a controlled environment within which the researcher manipulates the iv and records the effect on the dv,whilst maintaining strict control of extraneous variables
Strength of laboratory experiments
-High control over extraneous variables =researchers can ensure that any effects on the dv is likely to be the result of manipulation of the iv=researchers can establish a cause and effect relationship between the iv and dv=the experiment has high internal validity
Replication is more possible than other type of experiment because of the high levels of control+ standardisation=new extraneous variables are not introduced when repeating the experiment =replication is vital to check if findings are valid and not just one off
Limitation of laboratory experiments
Lacks generalisability.-as the environment is artificial is does not mirror everyday situations =in an unfamiliar contexts participants may behave in unusual ways=behaviour cannot be generalised beyond the research setting =experiment has low ecological validity
High demand characteristics=participants are aware they are being tested=participants may find cues from the research situation or the researcher that may be interpreted as revealing the purpose of the investigation =this as a result may cause participants to change their behaviour to try and suit the aims of the researcher
What is a field experiment
An experiment where the researcher manipulated an IV in a natural everyday life setting and records the effect on the DV
Strength of field experiment
Higher ecological validity-= participants are more likely to show their authentic behaviour as they are in their natural everyday setting=participants are unaware that they are being studied =behaviour is not being altered = findings can be generalised
No artificial material=^mundane realism as study represents real life
Limitation of field experiment
Low internal validity -as there’s increases realism researchers have a loss of control over extraneous variables =researchers may find it difficult to establish a cause and effect relationship between the iv and dv as there are other factors affecting behaviour
Ethical issues=if p’s are unaware they are being studied they cannot consent to being studied =the research might constitute an invasion of privacy
What is a quasi experiment
An study that has IV based on existing personal characteristics between people (age gender)
Strength of quasi experiment
-Only way to study the effect of personal characteristics on behaviour
-carried out under controlled conditions =control over extraneous variables =any effects on the dv is likely the result of manipulation of the iv=able to establish a cause an effect relationship
Limitation of quasi experiment
Participants can’t be randomly allocated to groups=uncontrolled participants variables may act as confounding variables =low internal validity=harder to establish cause effect
Natural experiment
An experiment where the iv is an event that has already taken place and cannot be manipulated.the research records the effect on the dv
(Used in cases where it wouldn’t be practical or ethical to manipulate the iv
Strengths of natural experiment
-provides opportunities for research that may not otherwise be undertaken from practical or ethical reasons
E.g institutionalisation of Romanian orphans
-^external validity=involve studies of real-life issues and problems
Limitation of natural experiment
-a naturally occurring event may only happen very rarely =reduces the opportunities for research=limits the scope for generalising findings to other similar situations
-participants may not be randomly allocated to experimental conditions =cannot control for participants variables =unable to establish the cause and effect relationship between the iv and dv
