Lab Experiment

9 Key excerpts on "Lab Experiment"

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  eBook - ePub

  Great Ideas in Psychology

  A Cultural and Historical Introduction

  • Fathali M. Moghaddam(Author)
  • 2013(Publication Date)
  • Oneworld Publications

    (Publisher)

  2

  THE PSYCHOLOGY LABORATORY

  For thousands of years philosophers speculated about the characteristics of human thought and action, but it is only relatively recently that systematic and controlled methods for testing such speculations have been developed. The progress made by modern psychology has been possible because of one method in particular: the psychology laboratory experiment , an experiment conducted in a separate physical space in which all the important characteristics can be controlled. The laboratory has gained a uniquely important place in psychology. The currently dominant school of psychology, cognitive psychology, relies heavily on the laboratory method. The cognitive approach pervades all research domains, including the domain of social psychology , the scientific study of individual behavior in social contexts, where over eighty percent of studies are conducted in the laboratory. What explains this dominance of the laboratory method in psychology? Why are survey methods, or observation methods, or open interview methods, or discourse analysis methods not the most often used by psychologists?

  A major reason for the popularity of the laboratory method is the superior level of control achieved by studying specific features of the individual isolated in a laboratory, relative to that achieved in other research methods, including surveys, observational procedures, and interview methods. Through a high level of control of all the factors in a situation, researchers can examine connections between independent variables, assumed causes, and dependent variables, assumed effects. This I call the causal assumption , which proposes that all behavior is determined by cause(s). Greater control achieved in the laboratory leads to higher reliability , meaning that experimental procedures can be replicated and results can be repeated. However, critics have raised questions about validity

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  Experimental Design in Psychology

  A Case Approach

  • M. Kimberly MacLin(Author)
  • 2023(Publication Date)
  • Routledge

    (Publisher)

  The second principle upon which scientific methodology relies is that observations from our senses are organized logically into a structure of knowledge. Frequently in experimental psychology, these structures of knowledge are called models. Cognitive psychologists may, for example, develop a model of memory based on observations of two types of memory and the laws that govern their relationship and the storage of information. Models are created from observations, and ultimately, may become complete enough to be theories. A major tenet of the scientific method is to subject theories to testing and possible disconfirmation.

  Scientific methodology consists of a variety of techniques, approaches, strategies, designs, equipment, and rules of logic. These vary from problem to problem and discipline to discipline. This book gives you an overview of the experimental techniques used in psychology.

  Experimental Design

  Let’s begin with a textbook definition of experimental design in psychology, the design of controlled conditions under which one might make empirical observations of actions, thoughts, or behavior of humans or animals. Scientific experiments are based on controlled observations. Inferences can then be made about the differences between observations. These inferences can be used to develop theories and to generalize to other similar situations (Platt, 1964 ). Experimental design refers to the context that the experimenter sets up to observe the contrasts (the differences) in observations. This requires holding as many conditions constant as possible in the situation, such that anything that varies between groups is predefined and controlled by the experimenter. The manipulated variable is called the independent variable and what is being measured is called the dependent variable

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  Social Scientific Research

  • Dawn Brancati(Author)
  • 2018(Publication Date)
  • SAGE Publications Ltd

    (Publisher)

  In laboratory experiments, these tasks generally involve participants playing a game, reading a vignette, looking at images, or watching a video. Participants’ responses to these stimuli can be measured in terms of the outcome of the game, the participants’ behaviors in subsequent tasks, and their responses to survey questions, among other things. Lab Experiments are especially useful when experimental manipulations do not exist in the real world, as in the case of a particular voting system, and cannot be studied through observational approaches as a result.

  Laboratory experiments have been used to understand human behavior on a wide range of subjects. In political science, they are commonly used to understand voting decisions under different electoral rules. In business and economics, instead of voting decisions, laboratory experiments are commonly used to understand financial decisions under different incentive structures. In psychology, meanwhile, laboratory experiments are often used to understand attitudes and bias, and in education, they are frequently used to understand learning outcomes and the psychological factors involved in them.

  Laboratory experiments have a number of advantages over other types of experiments. With Lab Experiments, researchers are better able to ensure that the experiment is administered properly than with other types of experiments. In Lab Experiments, researchers are more capable of ensuring that individuals are fully randomized to treatment and control groups, that every individual in the explanatory condition receives the same treatment and complies with it, that individuals in the control condition do not inadvertently receive the treatment, and so forth.

  The high degree of discretion that researchers enjoy in laboratory experiments also allows researchers to analyze more variation in experimental conditions than is often possible in field experiments. In a laboratory experiment on investment, for example, researchers could test the effectiveness of multiple different types of financial programs that encourage people to invest more and spend less simply by having subjects play different games for each type of inventive structure. In a field experiment, to do the same study, researchers would have to convince multiple governments, banks, or development agencies to adopt different programs with a range of investment incentives, and to accept the financial risk of doing so should the programs fail.

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  The First Century of Experimental Psychology

  • Elliot Hearst, Eliot Hearst(Authors)
  • 2019(Publication Date)
  • Routledge

    (Publisher)

  Behavior, as the term is used here, is broadly conceived, referring not only to actions constituting the organism’s current adjustment to the demands of its environment but also to the processing and storage of information relevant to long-term adjustment of the individual and, in the case of human beings, society.

  Much of the soul searching and qualms about the future of experimental psychology seems to arise not from observations of failure of the basic methods and approach, but rather from feelings on the part of many psychologists that the methods should not work as well as they actually have and surely cannot continue to do the same. In view of the many lessons from ethology that the behavior of organisms cannot be fully understood without adequate appreciation of their normal environmental settings and the behavioral tendencies and organizations characteristic of their species, how can it be possible to arrive at behavioral or psychological laws of real generality by examining arbitrarily selected samples of behavior in artificial laboratory environments? And considering the accumulating demonstrations by the currently flourishing discipline of developmental psychology that nearly all adult behavior of any complexity is strongly conditioned by individual learning histories, how could there be psychological laws or principles that cut across individual differences in past experience?

  Investigators close to the mainstream of experimental psychology have been as aware as others of these apparent paradoxes, but rather than being swayed by philosophical arguments they have tended to seek constructive solutions. One form that these efforts have taken during the last decade is the distinction between structural and control processes elucidated by Atkinson and Shiffrin (1968). The distinction took hold rapidly among cognitive psychologists and those associated with the information-processing movement and, by the end of the decade, has even begun to penetrate investigations of animal learning and memory. By control processes one understands the habits (especially pertaining to stimulus selection), criteria, strategies, and heuristics that enter into virtually all behavior of much intrinsic interest outside of the laboratory and certainly all that would be termed cognitive or intellectual in the usual meaning of these terms.

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  Applied Child Study

  A Developmental Approach

  • Anthony D. Pellegrini, David F. Bjorklund(Authors)
  • 1998(Publication Date)
  • Psychology Press

    (Publisher)

  Despite this commonsense approach, there seems to be a “paradigm war” (Gage, 1989) raging between experimentalists and interpretive, naturalistic researchers, especially in the area of educational research. Although polemics are helpful at the beginning of major disagreements between groups so that they can each define themselves clearly, at this point we should recognize that there is no one “silver bullet” or crystal ball that will provide all the answers. We should draw what we can from each approach to help us better understand the complexities of childhood.

  SOME BASIC PREMISES OF EXPERIMENTAL METHODS

  Whereas naturalistic approaches attempt to study children in the everyday environment, the experimental approach attempts to create an experimental, often contrived, environment in which to examine children. Aspects of the environment thought to affect children’s behavior are manipulated and controlled. Through manipulation and control researchers can make causal inferences about these manipulations.

  Experimental environments can be real classrooms, as in the cases of field experiments of curriculum and design (P.K.Smith & Connolly, 1980), laboratories, where children are taken from their natural habitats and studied (Pellegrini & Perlmutter, 1989), or hybrid designs where parts of classrooms are experimentally controlled and manipulated (I.Jones & A.D.Pellegrini, 1996). These terms manipulate and control are crucial to the experimental method, and are discussed in greater depth later because they help us make causal inferences about sets of variables.

  Generally, experiments are conducted in order to isolate specific cause-effect relationships. That is, experimenters attempt to identify the effects of certain independent variables (e.g., crowding) on behavior, or dependent variables (e.g., children’s aggression). The independent variables are manipulated to examine their effect on the dependent measure. Other, extraneous, variables are controlled so that they do not influence the relation between independent and dependent variables, and thus cloud the causal picture. Experiments that give us insight into the effects of an independent variable on a dependent variable, without confounding effects of extraneous variables, are said to be internally valid.

  Experiments are thus most beneficial where the investigator is interested in identifying such cause-effect relationships. Further, experiments can be conducted only in situations where investigators are free to manipulate and control aspects of the children’s environment. For example, to investigate the cause-effect relationhip between certain styles of teachers’ reading books to children and children’s literacy, the investigator must be free to vary, or manipulate, different reading environments.

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  Ethical Issues in Psychology

  • Philip Banyard, Cara Flanagan(Authors)
  • 2013(Publication Date)
  • Routledge

    (Publisher)

  For example, Ainsworth's Strange Situation (described on p. 25) involved recording infant behaviors in a very prescribed environment – the research room was a limited space (a 9 × 9 foot square) in order to prevent infants from wandering off. The space was divided into 16 smaller squares to help in recording the infant's movement. Bandura's well-known Bobo doll studies are another example of a controlled observation conducted in a laboratory – actually, an experiment that used controlled observation to measure the dependent variable if we want to be picky. KEY TERMS Laboratory A specially constructed environment where conditions can be carefully controlled. It is also used for observational studies such as a study of sleep patterns. Experiment A research method to investigate causal relationships by observing the effect of an independent variable on the dependent variable. Controlled observation A form of investigation in which behavior is observed but under controlled conditions, as opposed to a naturalistic observation. Dependent variable (DV) depends in some way on the independent variable (IV). The DV is measured in some way to assess the effects of the IV. Field study Any study that is conducted outside a laboratory (i.e. not in a specially designed environment). This includes field experiments, naturalistic observations and case studies. The argument is that merely placing a study in a laboratory does not make it unethical. Laboratories simply increase our ability to control variables, which is a necessary part of good research. Equally, a study using an experimental technique is not unethical because it is an experiment – what we want to focus on are the particular features in any study that raise ethical concerns. Field studies Some field studies are experiments (such as Bickman's field experiment about obedience to authority, described on p

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  Recipes for Science

  An Introduction to Scientific Methods and Reasoning

  • Angela Potochnik, Matteo Colombo, Cory Wright(Authors)
  • 2018(Publication Date)
  • Routledge

    (Publisher)

  Non-experimental studies may be called for when performing an intervention needed of investigate a hypothesis experimentally is unethical, impractical, or downright impossible. Suppose you are investigating whether major childhood stress decreases life span. The relevant intervention, imposing on an experimental group of children distressing conditions like parental death, extreme poverty, or poor nutrition, would be morally repugnant. Other interventions are impractical. Space exploration provides many straightforward examples. In 1975, two probes—Viking 1 and Viking 2—were launched to conduct experiments on Mars aiming to determine whether the chemical makeup of Mars’s soil supports microbial life. A year after launch, the probes landed and conducted their experiments, but they returned negative or inconclusive results. The cost of designing and constructing a new probe, the time needed to travel to Mars, and other limitations weighed against repeating the experiments. In the end, NASA’s next successful Mars landing wouldn’t be for another 20 years, in 1996, and then nearly another 20 years passed before the Mars Curiosity rover became operational (at a cost of $2.5 billion). Finally, some interventions are literally impossible to conduct because of the laws of nature. Astrophysicists and cosmologists have long pondered the nature of black holes, which have such strong gravitational fields that they bend the surrounding space-time, so that all light and matter spiral inescapably into them. No one can possibly be in the right position to directly observe this, let alone to intervene on it.

  In the Lab or in the Field?

  We have noted that some experiments occur in laboratories and others are field experiments, occurring in the outside world. There are advantages and disadvantages to each approach.

  Figure 2.7 Mars Curiosity rover selfie taken on Mount Sharp (Aeolis Mons) on Mars in 2015

  Laboratory experiments give researchers control over many aspects of the experiment, specifically over any interventions performed and the direct and indirect control of many extraneous variables. Depending on the nature of the experiments, a lab’s design features may include constant temperature, sterile environment, special equipment to produce unusual conditions, or, for experiments with human subjects, carefully selected lighting and furniture, soundproofing, and experimenters’ confederates who behave in a specified way. Those design features, and the control they provide, constitute one of the greatest advantages of the laboratory. Laboratory conditions are designed to control extraneous variables, to aid in detection and measurement of focal variables, and to create unique situations that don’t often or ever occur outside the lab. These features can enable scientists to discover regularities that are not easy to discern in the outside world.

  The high degree of control enabled by laboratory conditions brings with it a high degree of internal experimental validity

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  The Conduct of Inquiry

  Methodology for Behavioural Science

  • Abraham Kaplan(Author)
  • 2017(Publication Date)
  • Routledge

    (Publisher)

  Plainly, the distinction is very much a matter of degree. Its usefulness depends largely on the extent to which the subject being experimented on is responsive to those features of the context that have been controlled. The difference between field and laboratory experiments is therefore least likely to be important for physical science, more so for biological science: some animals, for instance, will not breed in captivity, so that their courtship and mating patterns cannot easily be subjected to laboratory experiment. When it comes to human beings, such difficulties scarcely need elaboration. Wherever experiments can be performed they are preferred to field studies, for they allow us to study precisely those factors in which we are most interested, and to differentiate between the dependent and the independent variables. And wherever laboratory experiments can be performed they are preferred to field experiments, for they allow us more readily to subject to controls whatever factors we choose, and to subject the others to more subtle variation. The question is recurrently raised, however, whether experimentation is possible in behavioral science at all. On this matter my own attitude is that of the backwoodsman who, asked whether he believed in baptism, replied, “Believe in it? Man, I’ve seen it done!” Yet there certainly are distinctive difficulties. Among these, the most commonly spoken of are the complexity and variability of social phenomena, as described, for instance, by Mill (94:574) : “the impossibility of ascertaining and taking note of all the facts of the case, and (those facts being in a perpetual state of change) [the situation that] before sufficient time had elapsed to ascertain the result of the experiment, some material circumstances would always have ceased to be the same”. The complexity, to be sure, is real

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  Testament for Social Science (RLE Social Theory)

  An Essay in the Application of Scientific Method to Human Problems

  • Barbara Wootton(Author)
  • 2020(Publication Date)
  • Routledge

    (Publisher)

  In this context, devotees of racing and of football pools should be a lesson to us. The data on which they have to work are generally such as only permit forecasts of very low probability. Nevertheless, thousands of enthusiasts study form with meticulous care in the hope of raising a small chance into one slightly larger. And where there is little to be gleaned from the actual data, they are eager to get all the help that they can from mathematical in their

  In any case, the complexity of the conditions to be unravelled in human problems varies greatly in different cases. We should do well to get ahead with those that are comparatively simple, the more so as these often turn out to be directly related to the other more complicated tasks. Psychology is the one human science that can to some extent avail itself of laboratory experiments, and can, therefore, study, under controlled conditions, certain carefully isolated aspects of human behaviour. In this way a body of knowledge is in process of being built up showing what human beings really are like. If the social scientists are not yet ready to make pronouncements on larger issues such as the psychological causes of war, let us remember that the physicists had to engage in most elaborate studies of minutiae before they could produce results that would blow up the world. Laboratory experiments, and near-laboratory work such as the close observations of individuals made by psychiatrists, are beginning to enable us to classify temperaments, to measure intelligence, to distinguish between hereditary traits and those that are environmentally produced, and to map the conditions with which guilt and aggression are associated. Knowledge on these topics is the basis of understanding of the larger problems of, say, government and economic relationships, just as the work of the cultural anthropologists is the beginning of wisdom in international affairs.

  Psychology is, indeed, so demonstrably the foundation of the social sciences that it is from many points of view to be regretted that these are not all regarded as branches of it. This is not just a matter of convenience of academic classification; for there is a real risk that other studies will go wrong because their psychology is false. In the absence of scientific knowledge based on accurate empirical observations, historians, economists and political theorists have worked on a few crude assumptions about human nature. They have, in consequence, only too often produced sweeping interpretations or intricate intellectual systems far removed from actuality. Man is neither wholly brutish and nasty, nor completely dominated by the economic calculus; and he will not learn how to govern himself satisfactorily or to satisfy his bodily needs until he has a much clearer idea about the proportions in which these and other ingredients are compounded in his make-up, and the measure in which the mixture can be modified to taste.

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