Branch or type of psychology concerned with employing empirical principles and procedures in the study of psychological phenomena. The experimental psychologist seeks to carry out tests under controlled conditions in order to discover an unknown effect or law, to examine or establish a hypothesis, or to illustrate a known law. The areas of study that rely most heavily on the experimental method include those of sensation and perception, learning and memory, motivation, and physiological psychology. Experimental approaches are also used in child psychology, clinical psychology, educational psychology, and social psychology.
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Experimental psychology is a methodological approach rather than a subject and encompasses varied fields within psychology more broadly, many of which are studied using other methodologies like hermeneutics. Experimental psychologists have traditionally conducted research, published articles, and taught classes on neuroscience, developmental psychology, sensation, perception, consciousness, learning, memory, thinking, and language. Recently, however, the experimental approach has extended to motivation, emotion, and social psychology.
While the origins of experimental psychology can be traced as far back as the eleventh century, when Ibn al-Haytham (Alhacen) used an experimental approach to visual perception and optical illusions in the Book of Optics in 1021 and Abū Rayhān Bīrūnī discovered the concept of reaction time, experimental psychology emerged as a modern academic discipline in the 19th century when Wilhelm Wundt introduced a mathematical and experimental approach to the field and founded both the first psychology labratory in Leipzig, Germany and the structuralist school of psychology. Other early experimental psychologists, including Hermann Ebbinghaus and Edward Titchener, included introspection among their experimental methods.
In the first half of the twentieth century, behaviourism became a dominant paradigm within psychology, especially in the United States. This led to some neglect of mental phenomena within experimental psychology. In Europe this was less the case, as European psychology was influenced by psychologists such as Sir Frederic Bartlett, Kenneth Craik, W. E. Hick and Donald Broadbent, who focused on topics such as thinking, memory and attention. This laid the foundations for the subsequent development of cognitive psychology.
In the latter half of the twentieth century, the phrase "experimental psychology" has shifted in meaning due to the expansion of psychology as a discipline and the growth in the size and number of its sub-disciplines. Experimental psychologists use a range of methods and do not confine themselves to a strictly experimental approach, partly because developments in the philosophy of science have had an impact on the exclusive prestige of experimentation. In contrast, an experimental method is now widely used in fields such as developmental and social psychology, which were not previously part of experimental psychology. The phrase continues in use, however, in the titles of a number of well-established, high prestige learned societies and scientific journals, as well as some university courses of study in psychology.
The complexity of human behaviour and mental processes, the ambiguity with which they can be interpreted and the unconscious processes to which they are subject gives rise to an emphasis on sound methodology within experimental psychology.
Control of extraneous variables, minimizing the potential for experimenter bias, counterbalancing the order of experimental tasks, adequate sample size, and the use of operational definitions which are both reliable and valid, and proper statistical analysis are central to experimental methods in psychology. As such, most undergraduate programmes in psychology include mandatory courses in Research Methods and Statistics.
While other methods of research - case study, correlational, interview, and naturalistic observation - are practiced within fields typically investigated by experimental psychologists, experimental evidence remains the gold standard for knowledge in psychology. Many experimental psychologists have gone further, and have treated all methods of investigation other than experimentation as suspect. In particular, experimental psychologists have been inclined to discount the case study and interview methods as they have been used in clinical.
Three days before his death, radical behaviourist B.F. Skinner criticized experimental psychology in a speech to the American Psychological Association for becoming increasingly "mentalistic" - that is, focusing research on internal mental processes instead of observable behaviours. This criticism was levelled in the wake of the cognitive revolution wherein behaviourism fell from dominance within psychology and functions of the mind were given more credence.
Study results from Ghent University, Department of Experimental Psychology broaden understanding of experimental psychology.(Report)
Dec 02, 2008; New research, 'The word grouping hypothesis and eye movements during reading,' is the subject of a report. According to recent...
Research reports from University of Bristol, Department of Experimental Psychology provide new insights into experimental psychology.
Jan 28, 2008; A new study, 'Teaching adults new words: the role of practice and consolidation,' is now available (see also Experimental...