Turned a light on and off quickly in a darkened room? Experimental psychology refers to the area of study focused on psychological research, as distinct from counseling or clinical psychology. Programs prepare students for careers in research and teaching.
Empiricism[ edit ] Perhaps the most basic assumption of science is that factual statements about the world must ultimately be based on observations of the world. This notion of empiricism requires that hypotheses and theories be tested against observations of the natural world rather than on a priori reasoning, intuition, or revelation.
Testability[ edit ] Closely related to empiricism is the idea that, to be useful, a scientific law or theory must be testable with available research methods. If a theory cannot be tested in any conceivable way then many scientists consider the theory to be meaningless.
Testability implies falsifiabilitywhich is the idea that some set of observations could prove the theory to be incorrect. Determinism[ edit ] Experimental psychologists, like most scientists, accept the notion of determinism.
This is the assumption that any state of an object or event is determined by prior states. In other words, behavioral or mental phenomena are typically stated in terms of cause and effect.
If a phenomenon is sufficiently general and widely confirmed, it may be called a "law"; psychological theories serve to organize and integrate laws. Parsimony[ edit ] Another guiding idea of science is parsimony, the search for simplicity.
For example, most scientists agree that if two theories handle a set of empirical observations equally well, we should prefer the simpler or more parsimonious of the two.
A notable early argument for parsimony was stated by the medieval English philosopher William of Occam, and for this reason the principle of parsimony is often referred to as Occam's razor. Tolman and Clark Hull popularized the idea of operationism, or operational definition.
Operational definition implies that a concept be defined in terms of concrete, observable procedures. Experimental psychologists attempt to define currently unobservable phenomena, such as mental events, by connecting them to observations by chains of reasoning. Experiment In experiments, human participants often respond to visual, auditory or other stimuli, following instructions given by an experimenter; animals may be similarly "instructed" by rewarding appropriate responses.
Since the s, computers have commonly been used to automate stimulus presentation and behavioral measurement in the laboratory. Experiments with humans may also obtain written responses before, during, and after experimental procedures. Psychophysiological experiments, on the other hand, measure brain or mostly in animals single-cell activation during the presentation of a stimulus using methods such as fMRIEEGPET or similar.
Control of extraneous variablesminimizing the potential for experimenter biascounterbalancing the order of experimental tasks, adequate sample sizethe use of operational definitionsemphasis on both the reliability and validity of results, and proper statistical analysis are central to experimental methods in psychology.
Because an understanding of these matters is important to the interpretation of data in almost all fields of psychology, undergraduate programs in psychology usually include mandatory courses in research methods and statistics.
A crucial experiment is an experiment that is intended to test several hypotheses at the same time. Ideally, one hypothesis may be confirmed and all the others rejected. However, the data may also be consistent with several hypotheses, a result that calls for further research to narrow down the possibilities.
A pilot study may be run before a major experiment, in order to try out different procedures, determine optimal values of the experimental variables, or uncover weaknesses in experimental design.
The pilot study may not be an experiment as usually defined; it might, for example, consist simply of self-reports.
Field experiments differ from field studies in that some part of the environment field is manipulated in a controlled way for example, researchers give different kinds of toys to two different groups of children in a nursery school.
Control is typically more lax than it would be in a laboratory setting. These are not experimental methods, as they lack such aspects as well-defined, controlled variables, randomization, and isolation from unwanted variables. Reliability and Validity[ edit ] Reliability[ edit ] Reliability measures the consistency or repeatability of an observation.
For example, one way to assess reliability is the "test-retest" method, done by measuring a group of participants at one time and then testing them a second time to see if the results are consistent.
Because the first test itself may alter the results of a second test, other methods are often used. For example, in the "split-half" measure, a group of participants is divided at random into two comparable sub-groups, and reliability is measured by comparing the test results from these groups, It is important to note that a reliable measure need not yield a valid conclusion.
To determine the validity of a measurement quantitatively, it must be compared with a criterion. For example, to determine the validity of a test of academic ability, that test might be given to a group of students and the results correlated with the grade-point averages of the individuals in that group.
As this example suggests, there is often controversy in the selection of appropriate criteria for a given measure. In addition, a conclusion can only be valid to the extent that the observations upon which it is based are reliable. Several types of validity have been distinguished, as follows: Internal validity[ edit ] Internal validity refers to the extent to which a set of research findings provides compelling information about causality.Social psychology is the scientific study of how people's thoughts, feelings, and behaviors are influenced by the actual, imagined, or implied presence of others.
In this definition, scientific refers to the empirical investigation using the scientific metin2sell.com terms thoughts, feelings, and behavior refer to psychological variables that can be .
In an experimental design scientists try to find an experimental hypothesis. To support their hypothesis scientists measures to find significant difference between experimental group and control group when measuring a dependent variable which can be influenced by independent variable.
A deeper understanding of the background and theoretical framework underpinning each specific approach is beyond the scope of this review and can be obtained elsewhere. The Journal of Experimental Psychology: General ® publishes articles describing empirical work that is of broad interest or bridges the traditional interests of two or more communities of psychology.
Clinical Psychology Review publishes substantive reviews of topics germane to clinical psychology. Papers cover diverse issues including. As part of their research program, many students are instructed to perform a literature review, without always understanding what a literature review is.