Experiments

Overview
In an experiment, the researcher manipulates the independent variable(IV) to see if a change can be induced in the dependent variable(DV) while confounding variables are sometimes controlled. Experiments aim to test the relationship between variables, which can be either:
 * Correlations: two or more things occur at roughly the same time. This suggests a possible relationship that is not necessarily causal.
 * Causation: when A happens, B must follow as B is caused by A. This suggests a relationship of causal and predictive nature.

Laboratory experiments
Lab experiments takes place in a laboratory, where conditions can be monitored and controlled. An example of a lab experiment is Bandura et al.'s (1963) 'Bobo doll experiment'. It showed how violent behaviour represented in the media(IV) can affect children's behaviour(DV). Three experimental groups and a control group were used. Bandura et al. found at worst a correlation and, at best, a causal relationship between seeing violence and acting violently. To further separate correlation from causality, the test-retest method can be used. If replicating the experiment (with different participants, for example) constantly achieve the same result, the relationship established is more likely to be causal.
 * Experimental group: subjects of the experiment. IV is manipulated (in this case, films depicting violent behaviours were shown to the children)
 * Control group: another group with matched characteristics of the experimental group, however, the IV will not be manipulated (in this case, the children were not shown violent film)

Strengths

 * Easy to replicate
 * Can establish cause-and-effect relationships

Limitations

 * Hawthorne/observer effect
 * Artificial environment reduces ecological validity

Field/natural experiments
Field/natural experiments take place in a natural setting, which is much more commonly used than lab experiments in Sociology. Since it's more difficult to exert control over the environment/conditions, correlations rather than causations are more likely to be established.

Rosenthal and Jacobson(1968) conducted a field experiment inside a school on how expectations from the teachers about the ability of their pupils(IV) can affect the educational achievement of the pupils(DV). They gave a sophisticated IQ test to the pupils, randomly selected some students and then told the teachers that those students would display 'dramatic intellectual growth'. They retested the pupils at a later date and found a significant increase in the IQ scores of the 'late-developers'.

Strengths

 * High ecological validity
 * Participants behave more naturally if unaware of being studied

Limitations

 * Less likely to control the conditions
 * Unethical to study participants (if) without consent