Historical Roots of Applied Experimental Psychology Psychology Of course, not everyone will agree on what constitutes an applied or an experimental study, so our estimates are subjective, but we considered roughly 10% of the 62 articles (not counting discussions) published in the first two volumes of the Journal of Experimental Psychology to be applied in the sense that the authors appeared to have been motivated, at least in part, by an interest in some practical problem and discussed how their results might be applied to it The majority of articles lack any explicit mention of the relevance of the findings to any practical ends; this is not to suggest that the investigators had no interest in practical issues, but only to note that they did not emphasize them in reporting their experiments Examples of studies we classified as applied for purposes of this exercise are shown in Table 24.1 “Experimental” was given a relatively broad connotation for determining appropriateness for the Journal of Experimental Psychology Many of the articles in the first two volumes of the journal did not report experimentation in the strict sense of involving controlled manipulation of variables, use of control groups, and so on Several of the reported experiments were relatively informal About one quarter of the articles focused on methodology; some described puzzles designed for testing purposes; and several others involved mental testing TABLE 24.1 Examples of Articles with an Emphasis on Applications in the First Two Volumes of the Journal of Experimental Psychology (1916–1917) Author Title Kent (1916) A graded series of geometric puzzles Subject Evaluation of geometric puzzles for use in a nonverbal test of intelligence Haines Relative values of Exploration of the utility of a (1916) point-scale and year-scale modified Binet-Simon measurements of 1,000 intelligence test for minor delinquents identifying mental deficiency among delinquent minors Burtt The effect of uniform and Evaluation of safety (1916) nonuniform illumination implications of an upon attention and experimental street lighting reaction times, with system in the field and in special reference to street the laboratory, as indexed illumination by reaction time to an auditory stimulus H F Adams The memory value of mixed Investigation of dependence (1917) sizes of advertisements of memorability of ad on its size and one’s frequency of exposure to it Marston Systolic blood pressure Investigation of effects on (1917) symptoms of deception systolic blood pressure of “lying” or telling the truth in an experimental situation 653 TABLE 24.2 Examples of Experimental Articles in the First Two Volumes of the Journal of Applied Psychology (1917–1918) Author Title Subject Geissler (1917a) Association-reactions applied to ideas of commercial brands of familiar articles Handwriting disguise Investigation of reasons for differential recall of common brand names Investigation of ability of people to disguise their handwritings and of judges to match disguised and undisguised hands Study of correspondence between judgments of tactile pressure, line length, auditory intensity, and brightness Demonstration of ease with which expressions using double or complex negatives are misinterpreted Downey (1917) Stevenson (1918) Correlation between different forms of sensory discrimination Wembridge Obscurities in voting upon (1918) measures due to doublenegative Of 67 articles published in the first two volumes of the Journal of Applied Psychology, a large majority would not be considered experimental in the narrowest sense of the term (but as we have noted, many of the articles appearing in the early issues of the Journal of Experimental Psychology probably would not pass that test either) We estimate that not more than 10% would be considered experimental in a sense that would make them appropriate for any of the Journals of Experimental Psychology today Articles included observational studies, anecdotal reports, essays, position papers, and descriptions of tests, training courses, and research plans Examples of studies that we consider most likely to be judged by experimentalists to be experimental are shown in Table 24.2 Experimental Psychology in World War II Controlled experimentation was being used to investigate the effects of various situational factors on human performance before World War II—examples of this work include studies by McFarland (1932) on the effects of oxygen deprivation and those by Fletcher and Munson (1933, 1937) on the masking properties of auditory noise—but the war presented a need for many more studies of these sorts, and research efforts were mobilized on both sides of the Atlantic In Great Britain well-known experimental psychologists, including Sir Frederic Bartlett, Norman Mackworth, and J K W (Kenneth) Craik, played leading roles in this effort The main centers of activity were first at Cambridge University, under Bartlett, and later at the newly established Applied Psychology Research Unit (APRU) of the Medical Research Council, 654 Psychological Experimentation Addressing Practical Concerns also in Cambridge, under Craik The APRU went on to become a leading establishment in Great Britain for the scientific study of problems relating to the human use of technology Bartlett (1943, 1948) studied the effects of fatigue on human performance Mackworth developed the first laboratory tests designed to simulate the requirements for sustained attention when monitoring a radar screen and spawned the field of vigilance research (Mackworth, 1950) Craik abstracted the requirements of antiaircraft gunnery into laboratory tracking tasks and, through experiments using a simulated cockpit that he built, advanced understanding of perceptual-motor performance generally Not only did Craik (1947, 1948) contribute as an experimentalist, but his theoretical ideas, some of which were published after his untimely death in 1945, also were influential both in psychology and in the emerging area of feedback systems or cybernetics In the United States, S S Stevens collected at the Harvard Psychoacoustics Laboratory a cadre of psychologists who soon would become well known, including James Egan, Karl Kryter, J C R Licklider, George Miller, and Irwin Pollack Among other achievements, this group improved intelligibility-testing techniques and explored methods for improving the understanding of speech in aircraft cockpits (Egan, 1944; Miller, 1947) Licklider (1946) experimentally investigated peak clipping and discovered that he could enhance the intelligibility of speech in a radio transmission system by using signal power to increase the signal amplitude even though the system amplitude-handling capability was limited and peak clipping would result Harvard University had a broader contract with the National Defense Research Committee (NDRC) that included funding for the Electro-Acoustics Laboratory and the Radio Research Laboratory, as well as subcontracts with other university laboratories that were working on humanmachine interaction In early 1945, just before the end of the war, the NDRC was asked to fund a new activity examining behavioral issues in naval combat information centers Immediately after the war, this work was turned over to Johns Hopkins University, where Clifford Morgan, Alphonse Chapanis, Wendell Garner, John Gebhard, and Robert Sleight became key contributors in a laboratory that identified with most of the psychological issues associated with the design of large-scale systems with which people had to interact (Chapanis, 1999) The creation of this laboratory led to publication of “Lectures on Men and Machines: An Introduction to Human Engineering,” by Chapanis, Garner, Morgan, and Sanford in 1947, and then to the first text to use the title, Applied Experimental Psychology, by Chapanis, Garner, and Morgan in 1949 Another distinguished team, which included Paul Fitts and Arthur Melton, was assembled in Washington, DC, by J R Flanagan to develop improved methods for selecting and training Army Air Force pilots At the time, all testing was done with paper and pencil This group developed the first reliable apparatus tests for evaluating the skills associated with flying (Bray, 1948; Fitts, 1947a, 1947b) Psychological testing was also used in connection with the selection of officers and key military personnel in Germany at least during the early days of the war; however, test results served primarily to guide the clinical judgment of those responsible for personnel assignments “Concepts of objectivity, standardization, reliability and validity were almost entirely lacking” (Fitts, 1946, p 160) The psychological testing program was inexplicably abandoned in Germany in 1942 Postwar Developments The contributions of psychologists to the war effort in the United States were widely recognized; as a result, each military service set up a laboratory for the continued study of the behavioral and psychological issues relevant to equipment design In 1945 Paul Fitts became the first director of the Army Air Force Psychology Branch of the Aeromedical Laboratory at Wright Patterson Field in Ohio, while Arthur Melton became head of an Army Air Force program on personnel selection and training in San Antonio, TX In the same year, Franklin V Taylor, with the assistance of Henry Birmingham, established the first Navy human engineering program at the Naval Research Laboratory The following year, the Human Engineering Division of the Naval Electronics Laboratory was established in San Diego under Arnold Small The army’s Human Engineering Laboratory was formed by the Army Ordnance Corps at Aberdeen Proving Ground near Baltimore in 1952, initially under the direction of Ben Ami Blau In each of these establishments, the focus was on designing military equipment to make it easier for operational personnel to use and on improving the availability and readiness of the military forces through personnel selection and training In the military sphere human performance is pushed to its limits, and there is a need to understand what those limits are and how to design to take account of them It is significant that all the military services recognized the importance of human performance capacities and limitations in the operation of their equipment and began in-depth experimental investigations of them soon after World War II ended The desire among researchers with special interests in applied problems to be affiliated with associations that represented specifically those interests found expression in the establishment in Great Britain of the Ergonomics Research Status of the Field Today Society in 1949 In 1957 both Division 21 of the APA (then known as the Society of Engineering Psychologists, and now known as the Division of Applied Experimental and Engineering Psychology) and the Human Factors Society (now known as the Human Factors and Ergonomics Society) came into existence There now are numerous associations and societies of a similar sort in several countries, as well as organizations and journals, that represent more focused interests within applied experimental psychology broadly defined Although researchers who affiliate with these organizations continue to focus attention on implications of human capabilities and limitations for system and equipment design and operation, interests have broadened into process control, transportation systems, health systems, human-computer interaction (HCI), design for the aging population, and many other areas During the 1960s and 1970s the most significant stimuli to further growth in the field in the United States were associated with initiatives of various government regulatory organizations Many of these initiatives were stimulated by one or more levels of advocacy from the public sector For example, Ralph Nader’s 1965 book Unsafe at Any Speed and related advocacy led to the establishment of the National Highway Safety Bureau (NHSB) to carry out safety programs under the National Traffic and Motor Vehicle Safety Act of 1966 and the Highway Safety Act of 1966 In 1970 the National Highway Transportation Safety Administration was created as the successor to the NHSB The critical incident at the Three Mile Island nuclear power generation plant in 1979 marshaled the public support that led the Nuclear Regulatory Commission to establish a Division of Human Factors Safety in 1980 These agencies, which focused predominantly on issues of safety, recognized that accidents are seldom exclusively physical in origin—that they almost always involve human error and that an understanding of human sensory, cognitive, and motor processes is essential to reducing that error In the 1980s and 1990s, although safety was still an important focus, the emphasis shifted somewhat to questions of ease of use of products of technology, and increased attention was given to the user interface in computer software design Computers have become ubiquitous in the workplace and in the home Not only are desktop computers commonplace, but most modern appliances and workplace systems, from videocassette recorders and hospital patient monitors to automated teller machines and vehicle navigation systems, also have one or more computers embedded in them somewhere Usability has become a major objective of effective software design and evaluation, and many of the methods of experimental psychology have been adapted to respond to this need 655 STATUS OF THE FIELD TODAY How should we think of applied experimental psychology as it exists today? As a discipline (like high-energy physics or biochemistry)? An occupational specialty (like forensic psychology or vocational counseling)? A topical focus (like vision or working memory)? A methodology (like eyemovement tracking or evoked-potential recording)? We think it is none of these, but rather a domain of psychological research defined as experimentation with a practical purpose; it encompasses that work within experimental psychology that is motivated to a significant degree by practical concerns We say “to a significant degree” because we not wish to suggest that it is driven only by practical concerns; as already noted, we believe that much of the best applied work is motivated by, and contributes substantively to, both practical and theoretical interests Practical but Not Atheoretical The last point deserves emphasis Sometimes applied work is assumed necessarily to be atheoretical We take issue with this view It is possible for work to be motivated by the desire to answer an immediate practical question and to be atheoretical, and it is possible for work to be motivated by a purely theoretical question that has no obvious relevance to any real-world problem; but it is not essential that practical work be atheoretical or that theoretical work be divorced from applications Of special relevance to the focus of this chapter are numerous examples of theoretical ideas and constructs that have been put forth and developed by investigators who were keenly interested in practical problems and who were motivated to help solve them Among the names that come immediately to mind in this regard are Frederic Bartlett (1932, 1943, 1948), Paul Fitts (1951, 1954; Fitts & Seeger, 1953), and Donald Broadbent (1957, 1958, 1971) These and many other investigators who could be mentioned did work that simultaneously addressed theoretical and practical interests Among the theoretical ideas that have been closely associated with applied work—sometimes guiding that work and sometimes being informed by it—are theories of human motor skills, information theory (and communications theory more generally), detection and decision theory, and game theory An Interdisciplinary Field Much applied experimentation is interdisciplinary in the sense that addressing applied problems in specific domains 656 Psychological Experimentation Addressing Practical Concerns requires knowledge of those domains If, for example, one wishes to research on teaching or learning for the express purpose of helping to increase the effectiveness of classroom instruction, one must know more than a little about education from a practitioner’s point of view Or if one wants to work on the objective of decreasing the frequency of human error in the operating room or in the delivery of medical services more generally, one needs to know a lot—or to work with someone who knows a lot—about medical procedures and systems Many psychological researchers who work in highly applied areas, such as the human factors of aviation, nuclear power plant control, or manufacturing, have training both in psychology and in their area of application Others work as members of research teams that depend on domain specialists to contribute the domain-specific knowledge to the operation, but even here the psychologist is likely to need a more-than-passing acquaintance with the relevant disciplines in order to ensure a smoothly functioning and productive team endeavor Laboratory and Field Experimentation Experimentation, as we are using the term, includes both laboratory and field studies People doing applied research are keenly aware of the considerable differences that typically characterize laboratory and field work Variables are easier to control in the laboratory than in the field; as a consequence, the results of laboratory experiments typically are easier to interpret However, the increased control usually comes at the expense of less realism than one has in operational realworld situations, so while the laboratory results may be easier to interpret, they are likely to be harder to apply without qualification to the real-world situations of interest A strategy that has been recommended for applied research involves both laboratory and field research Hypotheses can be tested in a preliminary fashion in simplified or abstracted laboratory simulations of real-world situations, perhaps using students as participants, and then the findings can be checked with people functioning in their normal realworld contexts This approach is illustrated by the work of Gopher, Weil, and Bareket (1994) in checking the extent to which effects of training with a simulation of certain aspects of flight control transfer to performance in an actual flight situation Unfortunately, too often only the first step is taken, and the assumption is made that the results obtained will transfer to the operational situations of interest We believe that the development of a trustworthy store of psychological knowledge that can be applied in confidence to real-world problems requires a continuing interplay between laboratory and field experimentation where what is learned in each context is informing further work in the other, and theory is being refined by the outcomes of both types of research Closely Related Disciplines Defined as psychological experimentation that is explicitly addressed to practical concerns, applied experimental psychology overlaps considerably with several other disciplines Most obviously, it has much in common with human-factors psychology (which for purposes of this chapter can be considered synonymous with ergonomics or engineering psychology, although for some purposes somewhat different connotations are given to these terms; Nickerson, 1999; Pew, 2000; Wogalter, Hancock, & Dempsey, 1998) It intersects also with many subfields in psychology that are defined by a focus on an area of application, such as organizational/ industrial psychology, military psychology, aviation psychology, forensic psychology, consumer psychology, and the psychology of aging, among several others Researchers in each of these and other subfields conduct experimental studies addressed to practical questions of special interest to people involved in these areas and hence provide many examples of applied experimental psychology Employment The kinds of settings in which applied experimental psychologists work are as varied as are the fields of activity Many applied experimentalists work in universities, and their work is frequently associated with institutes or other organizations that specialize in applied work, perhaps with a specific focus, such as transportation, education, aging, disabilities, or computer technology Major employers of experimentalists are the various branches and research laboratories of the federal government Notable among these are the laboratories of the military services, the National Aeronautics and Space Administration, the Department of Transportation, and the National Institutes of Health Several for-profit and nonprofit companies provide opportunities for applied experimentalists These include the American Institutes of Research, Anacapa Sciences, and CHI Systems Many large corporations have human-factors groups that either work on their own in-house research and development programs or on systems-development projects done under contract for the government or other organizations Boeing and Lockheed-Martin in the aerospace industry and Ford and General Motors in the automotive industry are examples of such companies in the United States Productdevelopment projects may involve experimentation during Examples of Recent Applied Experimental Work design or concept development stages as well as during product test and evaluation Many organizations in the computer and communications industries, especially the software side of these industries, have vested interests in research on HCI and in the evaluation of product usability IBM, Xerox, Microsoft, and Sun Microsystems are notable among large companies that provide opportunities for research and development in this area However, while controlled experimentation has played, and continues to play, an important role in providing results that inform the design of user-friendly products, much of the testing and evaluation that is done is limited by costeffectiveness concerns to heuristic analyses or other shortcut methods based on the expert judgment of one or a few specialists (Nielson, 1994) The National Research Council’s Committee on Human Factors issued a report in 1992 that provides demographic information, including employment information, on human factors specialists, many of whom are applied experimentalists (VanCott & Huey, 1992) Other sources of information regarding where applied experimental psychologists work include P J Woods (1976), Super and Super (1988), and Nickerson (1997) EXAMPLES OF RECENT APPLIED EXPERIMENTAL WORK Applied experimental work is performed in essentially all areas of psychology Here our intent is to illustrate, by reference to specific studies, the range of subjects addressed We focus primarily on relatively recent work, but there is no paucity of comparable examples from earlier times, a few of which were mentioned in the section on the historical roots of applied experimental psychology It will be obvious from the examples given that applications of experimental psychology are not limited to the design of devices or systems that people use or with which they interact This is a major focus of human-factors or engineering psychology, but experimental psychology has many applications that not fall in this category 657 experimentation in this area is illustrated by the method of expanding practice first investigated by Landauer and Bjork (1978), and subsequently by Cull, Shaughnessy, and Zechmeister (1996) The method involves increasing the spacing between successive rehearsals of any given item in the list to be recalled, and it has proved to be effective in various contexts Another focus of research has been the keyword mnemonic of associating visual images with words that are to be learned Since it was originally proposed by Atkinson (1975), the method has been studied and applied in many contexts, including the learning of foreign-language vocabulary (Atkinson & Raugh, 1975), state capitals (Levin, Shriberg, Miller, McCormick, & Levin, 1980), and science vocabulary (King-Sears, Mercer, & Sindelar, 1992) Interest in determining the strengths and limitations of the method continues to motivate research (Thomas & Wang, 1996) The ability to associate names with faces—to remember the names of people to whom one has recently been introduced—is a sufficiently valuable social asset to have motivated many efforts to find ways to improve it (e.g., McCarty, 1980; Morris & Fritz, 2000) Morris and Fritz demonstrated that recall of the names of the members of a group of modest size can be enhanced by a simple game that applies the principle of expanding practice to the process of making introductions Other experimentally developed techniques for enhancing memory for names, often involving the use of imagery or word-image associations, have also proved to be effective (Furst, 1944; Morris, Jones, & Hampson, 1978) Researchers have shown great interest in the development of ways and devices to aid people—especially elderly people, but also people who maintain full and tight schedules—to remember to carry through on plans and intentions (e.g., to keep appointments, take medications, and perform timecritical tasks; J E Harris, 1978; Herrmann, Brubaker, Yoder, Sheets, & Tio, 1999; Kapur, 1995) The desirability of such aids is evidenced by the ease with which many people forget to keep appointments, take medications, and so on, without them Identification of the determinants of the effectiveness of proposed approaches and devices intended to aid prospective memory has been the focus of some experimentation (Herrmann, Sheets, Wells, & Yoder, 1997) Memory Enhancement Interest in the development of devices and procedures for enhancing memory (mnemonics) predates the emergence of experimental psychology as a discipline by many centuries, and the search for ways to improve memory continues to the present day (McEvoy, 1992; Wenger, & Payne, 1995; see also chapter by Roediger & Marsh in this volume) Recent Eyewitness and Earwitness Testimony Much experimentation has been done on eyewitness (Sobel & Pridgen, 1981; Wells, 1993) and earwitness (Bull & Clifford, 1984; Read & Craik, 1995; Olsson, Juslin, & Winman, 1998) testimony in recent years; these topics are of considerable practical interest because of their relevance to court ... objective of effective software design and evaluation, and many of the methods of experimental psychology have been adapted to respond to this need 655 STATUS OF THE FIELD TODAY How should we think of. .. in psychology that are defined by a focus on an area of application, such as organizational/ industrial psychology, military psychology, aviation psychology, forensic psychology, consumer psychology, ... demonstrated that recall of the names of the members of a group of modest size can be enhanced by a simple game that applies the principle of expanding practice to the process of making introductions