Disadvantaged (compared to Lab Experiments)
It is not possible to control variables as closely as with laboratory experiments – With the Rosenthal and Jacobson experiment, for example we simply don’t know what else might have influenced the ‘spurting group’ besides ‘higher teacher expectations’.
The Hawthorne Effect (or Experimental Effect) may reduce the validity of results. The Hawthorne effect is where respondents may act differently just because they know they are part of an experiment.
Ethical Problems – Just as with lab experiments – it is often possible to not inform people that an experiment is taking place in order for them to act naturally, so the issues of deception and lack of informed consent apply here too, as does the issue of harm.
Practical Problems – Access is likely to be more of a problem with lab experiments. Schools and workplaces might be reluctant to allow researchers in.
Rosenthal and Jacobson’s 1968 Field Experiment on Teacher Expectations (Pygmalion in the Classroom)
The aim of this research was to measure the effect of high teacher expectation on the educational performance of pupils.
Pupils were given an IQ test and on the basis of this R and J informed teachers that 20% of the pupils were likely ‘spurt’ academically in the next year. In reality, however, the 20% were randomly selected.
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 the spurters seem to have benefited from this study, the other 80% of pupils did not
reliability is a problem while the research design was relatively simple and thus easy to repeat
Take place in real life settings
The high street
More common than Laboratory
Because they are closer to real life
Advantages (compared to Lab Experiments)
Better external validity – The big advantage which field experiments obviously have better external validity than lab experiments, because they take place in normally occurring social settings.
Larger Scale Settings – Practically it is possible to do field experiments in large institutions – in schools or workplaces in which thousands of people interact for example, which isn’t possible in laboratory experiments.