Laboratory experiments Flashcards
Types of experiments
There are three main types of experiments
The Laboratory experiment, the field experiment and the comparative method.
Laboratory Experiments take place in an artificial, controlled environment such as a laboratory
Field Experiments – take place in a real world context such as a school or a hospital.
The comparative method – involves comparing two or more similar societies or groups which are similar in some respects but varied in others, and looking for correlations.
Experiments typically start off with a hypothesis which is a theory or explanation made on the basis of limited evidence as a starting point for further investigation. A hypothesis will typically take the form of a specific, testable statement about the effect which one or more independent variables will have on the dependent variable.
Field experiments
- Takes place in the subjects natural surroundings rather than artificial laboratory enviroment
- those involved usually not aware that they are subjects of experiment
The researcher manipulates one or more variables in situation to see what affect it has on subjects of experiment
Explain Rosenhan’s & Jacobsons Field experiment
Rosenthal and Jacobson’s field experiment on effects of teacher expectation
Aim-measure the effect of high teacher expectation on the educational performance of pupils.
Procedure
Rosenthal and Jacobson carried out research in California primary school
Pupils given an IQ test and on the basis of this R & J informed teachers that 20% of the pupils were likely ‘spurt’ academically in the next year.
In reality, however, the 20% were randomly selected.
All of the pupils were re-tested 8 months later those classified as spurters had gained 12 IQ points compared to an average of 8.
Rosenthal and Jacobsen concluded that higher teacher expectations were responsible for this difference in achievement.
Limitations of the Experiment
Deception/ Lack of Informed Consent is an issue: In order for the experiment to work, R and J had to deceive the teachers about the real nature of the experiment, and the pupils had no idea what was going on.
Ethical problems: while spurters benefited from this study,
the other 80% of pupils did not, they were harmed because of the teachers giving disproportionate amounts of attention to the spurting group.
Given that child rights and child welfare are more central to education today it is unlikely that such an experiment would be allowed to take place.
Reliability is a problem: while the research design was relatively simple and thus easy to repeat the exact conditions are not possible to repeat – given differences between schools and the type and mixture of pupils who attend different schools.
Finally, it’s not possible to rule out the role of extraneous variables. Rosenthal and Jacobson claim that higher teacher expectation led to the higher achievement of the ‘spurters’ but they did not conduct any observations of this taking place. It may have been other factors.
The comparative method
Is carried out in the mind of sociologist
It is a ‘thought experiment’-does not involve researcher experimenting on real people
It is designed to discover cause & effect relationships
step 1. Identify two groups that are alike expect for variable interested in
Step 2. Compare between the groups to see if this one difference between them has an effect
e.g of comparative method -Durkheims study of suicide
Durkeheims study of suicide
The comparative method
E.g of comparative method is Durkheims classic study of suicide
Durkheims hypothesis was that low levels of integration of individuals into social groups caused high rates of suicide
He argued that catholicism produced higher levels of integration than protestantism
he therefore predicted that protestants would have higher rates of suicide than catholics
He tested his prediction by comparing the sucide rates of catholicism & protestants who were similar (in terms of where they lived)
his prediction supported statistics which showed catholics have lower suicde rates
Evaluation of Durkehims comparitive method
In seeking to discover cause & effect relationships,the comparative method has three advantages:
it avoids artificiality , it can be used to study past events & imposes no ethical problmes
Limitation:
Comparative method gives researcher less control over variables
less certain whether a thought experiment really has discovered cause of something
Positivits view on laboratory experiments
positivists favour laboratory experiments -achieves their main goal of reliability
* careful control over experimental conditions & experimenter detachment produces reliable data because other researchers can replicate experiment
* Allows researcher to identify & measure behaviour patterns quantitatively & mainpulate variables to establish cause & effect relationships
* however positivists recognise that is impossible to control all variables
* therefore like compartive method more
Interpretivists view on laboratory experiments
Reject laboratory experiments because fails to achieve their main goal of validity
It is an artificial situation producing unnatural behaviour
Interpretivists favour naturalistic field experiments -but positivits criticise this because gives less control over variables
