by Saul McLeod, published 2007

Lab Experiment	Field Experiment
This type of experiment is conducted in a well-controlled environment – not necessarily a laboratory – and therefore accurate measurements are possible. The researcher decides where the experiment will take place, at what time, with which participants, in what circumstances and using a standardized procedure. See also - Experimental Design See also - Independent and Dependent Variable	These are conducted in the everyday (i.e. natural) environment of the participants but the situations are still artificially set up. The experimenter still manipulates the IV, but in a real-life setting (so cannot really control extraneous variables).
Case Study	Correlation
Case studies are in-depth investigations of a single person, group, event or community. Case studies are widely used in psychology and amongst the best-known ones carried out were by Sigmund Freud. He conducted very detailed investigations into the private lives of his patients in an attempt to both understand and help them overcome their illnesses. Case studies provide rich qualitative data and have high levels of ecological validity.	Correlation means association - more precisely it is a measure of the extent to which two variables are related. If an increase in one variable tends to be associated with an increase in the other then this is known as a positive correlation. If an increase in one variable tends to be associated with a decrease in the other then this is known as a negative correlation. A zero correlation occurs when there is no relationship between variables.
Interview	Questionnaire
Unstructured (informal) interviews are like a casual conversation. There are no set questions and the participant is given the opportunity to raise whatever topics he/she feels are relevant and ask them in their own way. In this kind of interview much qualitative (i.e. descriptive) data is likely to be collected. Structured (formal) interviews are like a job interview. There is a fixed, predetermined set of questions that are put to every participant in the same order and in the same way. The interviewer stays within their role and maintains social distance from the interviewee.	Questionnaires can be thought of as a kind of written interview. They can be carried out face to face, by telephone or post. The questions asked can be open ended, allowing flexibility in the respondent's answers, or they can be more tightly structured requiring short answers or a choice of answers from given alternatives. The choice of questions is important because of the need to avoid bias or ambiguity in the questions, ‘leading’ the respondent, or causing offence.
Observations	Observations
Covert observations are when the researcher pretends to be an ordinary member of the group and observes in secret. There could be ethical problems or deception and consent with this particular method of observation. Overt observations are when the researcher tells the group he or she is conducting research (i.e. they know they are being observed).	Natural: Here spontaneous behavior is recorded in a natural setting. Controlled: behavior is observed under controlled laboratory conditions (e.g. Bandura Bobo doll). Participant: Here the observer has direct contact with the group of people they are observing. Non-participant (aka "fly on the wall): The researcher does not have direct contact with the people being observed.
Content Analysis	Pilot Study
Content analysis is a research tool used to indirectly observe the presence of certain words, images or concepts within the media (e.g. advertisements, books films etc.). For example, content analysis could be used to study sex-role stereotyping. Researchers quantify (i.e. count) and analyze (i.e. examine) the presence, meanings and relationships of words and concepts, then make inferences about the messages within the media, the writer(s), the audience, and even the culture and time of which these are a part. To conduct a content analysis on any such media, the media is coded or broken down, into manageable categories on a variety of levels - word, word sense, phrase, sentence, or theme - and then examined.	A pilot study is an initial run-through of the procedures to be used in an investigation; it involves selecting a few people and trying out the study on them. It is possible to save time, and in some cases, money, by identifying any flaws in the procedures designed by the researcher. A pilot study can help the researcher spot any ambiguities (i.e. unusual things) or confusion in the information given to participants or problems with the task devised. Sometimes the task is too hard, and the researcher may get a floor effect, because none of the participants can score at all or can complete the task – all performances are low. The opposite effect is a ceiling effect, when the task is so easy that all achieve virtually full marks or top performances and are “hitting the ceiling”.

How to cite this article: McLeod, S. A. (2007). Simply Psychology; . Retrieved , from