Brunswik's lens model is a conceptual framework for describing and studying how people make judgments. For example, a person judging the size of a distant object, physicians assessing the severity of disease, investors judging the quality of stocks, weather forecasters predicting tomorrow's weather and personnel officers rating job candidates all face similar tasks. In each case, they must use whatever information is at hand ("cues") to make an inference about some unknown quantity. The cues for judgment are analogous to a lens through which the person views an unknown object.
Egon Brunswik developed the lens model as a representation of his theory of probabilistic functionalism, which describes how people function in an uncertain world. On one side of the lens is the environmental system that is the context for judgment. The other side of the lens is the cognitive system. The core of the lens model is the assertion that understanding judgment requires study of both sides of the lens.
The lens model is used to study multiple-cue judgments made under conditions of uncertainty and complexity. The person has several "cues" (i.e., items of information, or indicators) to rely on, and the cues are imperfect, fallible, indicators of an unknown attribute of some entity. Such judgments are pervasive and difficult.
As the lens model has been adapted and applied for various kinds of judgments, it has appeared in different versions that differ from Brunswik's original in form but not in substance. [1] [2] A modern version used by Cooksey [3] incorporates into Brunswik's original model later developments from Hammond's Social Judgment Theory (Figure 1).
The lens model represents the essential symmetry (the "principle of parallel concepts." [2] ) between the environment (left side of the model) and the person (right side of the model).
The cues (Xi) together make up the "lens" They are "proximal" because they are directly available to the person making a judgment. In the case of weather forecasting they would include today's temperature and other weather data. In the case of predicting college GPA, cues might include high school grades and test scores.
The lines from the cues converge on the object or event on the left that is the target of judgment. It is "distal," that is, it is not directly available to the person but must be inferred from the available cues. The criterion (Ye) is the true value of the attribute that is being judged. The criterion might be tomorrow's observed high temperature or the actual college GPA of an applicant upon graduation.
Lines from the cues also converge on the judgment (Ys) at the right. This is a person's inference about the unknown attribute based on the known cues.
The lines between the criterion and the cues represent "Ecological validities," [note 1] that is, the strength of the relations between the cues and the criterion. Similarly, the lines between the cues and the judgments represent "Cue utilizations," that is, the strengths of the relations between each cue and the judgment. [note 2]
The lines between the cues (rij) indicate that the cues themselves are not independent of each other. Typically they are correlated with one another.
The arc between the criterion and the judgment is achievement, or accuracy. It is typically measured by the correlation (ra) between Ye and Ys.
"Zones of ambiguity" exist between the cues and both the criterion and judgment. According to Hammond et al., [2] p. 272:
Knowledge of the environment is difficult to acquire because of causal ambiguity -- because of the probabilistic, entangled relations among environmental variables. Tolman and Brunswik called attention to the critical role of causal ambiguity in their article "The Organism and the Causal Texture of the Environment" (1935), [4] in which they emphasized the fact that the organism in its normal intercourse with its environment must cope with numerous, interdependent, multiformal relations among variables which are partly relevant and partly irrelevant to its purpose, which carry only a limited amount of dependability, and which are organized in a variety of ways. The problem for the organism, therefore, is to know its environment under these complex circumstances. In the effort to do so, the organism brings a variety of processes (generally labeled cognitive), such as perception, learning, and thinking, to bear on the problem of reducing causal ambiguity.
In research applications, individuals are typically asked to make judgments of many cases, typically 30 or more, each involving a different combination of values of the cues. The resulting data are analyzed separately for each individual using a statistical model such as multiple regression analysis. This technique, called judgment analysis, [3] yields measures of cue utilization and the fit of the model to the judgments.
Ideally, a parallel analysis is applied to the criterion based on the same combinations of cue values judged by the person. This results in measures of cue validity and the accuracy of the best fit model for combining the cues to produce a prediction of the criterion.
Once regression models are fit to both the judgment and the criterion, the lens model equation [5] [6] [7] can be used to analyze achievement into several components that are useful for understanding strengths and limitations of judgment processes, and how to improve them. [8]
Hammond [1] provides an excellent example of Brunswik's lens model applied to clinical psychologists' judgments about their patients (Figure 2). Each case presented to the psychologists included the values of four cues describing a patient. In this study, 10 clinical psychologists judged IQ based on patient responses to four Rorschach test factors ("Cues" X1 ...X4). Each clinician judged 78 patients based on the values of the four cues in their records. The clinicians' judgments of IQ (Ys in Figure 1) were then compared with patients' scores on a standard IQ test. The actual IQ test score was the objective outcome criterion (Ye in Figure 1). Each clinician's achievement (ra in Figure 1) was measured by the correlation between the clinician's judgments of IQ (Ys) and the patients' actual IQ test scores (Ye) for the 78 patients. The resulting median achievement was 0.47 across the 10 clinical psychologists. Correlational statistics and multiple regression analyses were also used to capture the relationships (e.g., correlations) among (1) each cue and clinician's judgments (cue utilization, Figure 1), (2) the cues and the environmental criterion—IQ test score (ecological validity, Figure 1), and (3) the correlations among the cues themselves (inter-cue correlations).
Early in his career, Egon Brunswik was concerned with perceptual constancy, or how people maintain coherence in a changing environment. During this period, Gestalt psychology was a dominant theory of perception. Gestalt psychologists investigated a broad spectrum of perceptual illusions, eventually evolving into an examination of errors in perception.
Some psychologists, including Brunswik and James. J. Gibson rejected the fixation on studying illusions, emphasizing instead the importance of investigating behavior in natural environments, a perspective that identified them as ecological psychologists. Brunswik's interest in understanding the relationship between an organism and its environmental structure can be traced back to his early collaboration with Edward C. Tolman in 1935. Their joint work, "The Organism and the Causal Texture of the Environment," [4] placed a spotlight on environmental texture. They posited that individuals strive to navigate through an environment composed of interconnected and "textured" objects and events.
This viewpoint contrasted with the prevailing trend among psychologists of that era, who were seeking principles of determinism as in the physical sciences, focusing on finding precise mathematical laws governing behavior. [9]
Brunswik conducted rat experiments in Berkeley that showed that rats adhered to a probability-matching rule, reflecting their assessment of the likelihood of obtaining food or other goals. Athanasou and Kaufmann (2015, Table 1) [10] describe the development of the probabilistic concepts during Brunswik's work that finally led to the lens model framework.
Brunswik's colleague, Fritz Heider, was a key figure in the development of the lens model. While Brunswik is often credited with the creation of the lens model, the collaborative efforts between the two researchers are often overlooked. It is misleading to attribute the lens model entirely to Brunswik as the concept of the lens model was initially introduced by Heider. [11] [12] Weiser [13] describes the intellectual context that influenced Brunswik's thinking and traces the evolution of the lens model from Heider's original hand-drawn figure in his private notebooks [14] to Brunswik's final version. He points out that Heider was not concerned with experimentation and quantification which were central to Brunswik's work.
Bernhard Wolf elucidates the inspirations behind the work of Brunswik and Heider in his 1995 book, "Brunswik and ökologische Perspektiven in der Psychologie" (Brunswik and Ecological Perspectives in Psychology). [15] [16] For more detail, see historical papers by Leary [17] and Radler. [18]
Since Brunswik developed the lens model to examine visual perception [19] it has been generalized to other kinds of judgments by Kenneth R. Hammond [2] [20] and others. As a result, some of Brunswik's original terms have fallen into disuse.
The "Initial focal variable" refers to a property of the object that is to be judged or perceived, e.g., size, weight, or distance from the observer. This is usually now called the distal variable, criterion, gold standard, or Ye. In Figure 3, "Vicarious mediation" refers to the variables that describe the object (proximal variables, cues, sensory cues, items of information) such as color, clarity, retinal image. They must mediate vicariously between the object and the person because, in Brunswik's view, direct perception is not possible. The object gives rise to the cues by some process ("Process detail") but there are other unknown variables that affect the cues ("Stray causes). The "Terminal focal variable" is the inference (perception, judgment, Ys) made by a person. The cues are combined into a judgment by some process ("Process detail"), but other unknown variables affect the judgment as well ("Stray effects"). The "Functional arc" represents achievement or accuracy, that is, the degree of match between the actual property of the object and the judgment of that property. Accuracy is the goal of the observer. "Feedback" typically refers to knowledge of results, often called "outcome feedback." However, in Brunswik's words: "A semicircular arrow is appended to the terminal focus to indicate that lens patterns do not stand in isolation but are apt to reflect back upon the person in a future state in what is now sometimes called a 'feedback loop..." (Brunswik, 1952, p. 20). [19] This suggests that Brunswik had something more in mind when he added the feedback arrow, perhaps related to his interest in cybernetics (Brunswik, 1956, p. 141). [21]
Brunswik described the concepts of stray causes and stray effects as follows: [19]
Impossibility of foolproof distal achievement. "Functional validity." Quasi-rationality .- In line with the inherent probability character of object-cue and of means-end relationships, gross organismic coming-to-terms with the environment can thus never become foolproof, especially so far as the more vital remote distal variables are concerned. It is in this sense that, as William James has phrased it, perception is "of probable things." In the terminology of Reichenbach's probabilistic empiricism, behavior and the inferences implicit in it must retain a certain "wager-" or "posit"-character. Perceptual and behavioral functioning is spoiled much in the manner in which stray rays ... are apt to interfere with perfect focusing. Imperfections of achievement may in part be ascribable to the "lens" itself, that is, to the organism as an imperfect machine. More essentially, however, they arise by virtue of the intrinsic undependability of the intra-environmental object-cue and means-end relationships that must be utilized by the organism .... (p. 23)
The terms "stray causes: and "stray effects" were replaced with the "zones of ambiguity" by Hammond et al. [2]
The lens model is a framework for understanding judgment and designing studies of judgment. It is not really a theory, but it embodies theoretical concepts of Egon Brunswik's Probabilistic functionalism.
The lens model embodies the central concepts of symmetry between the environmental system and cognitive system. There are imperfect relations between the cues and both the judgment and the object being judged, and cue validities on the environment side correspond with cue utilizations on the cognitive side.
As described above, the arc connecting the judgment and the criterion represents achievement, or accuracy of judgment. Brunswik called this "functional validity." [19] (p. 23):
"Achievement," in the sense of the probability for an initial focal event (say, a measured stimulus ) to be followed by its terminal counterpart (say, the correct perceptual estimate), may, then, be defined as "functional validity" and measured by a correlation coefficient.
(Although Brunswik embraced the correlation coefficient, there is nothing about the lens model that requires correlations. Correlations have some weaknesses [22] [23] and other measures may be more appropriate in certain contexts.)
The lens model's domain is achieving accuracy in a complex and uncertain world. Factors that limit achievement include: cues that are probabilistic indicators of the criterion, complex entanglement among cues and the criterion, missing cues, suboptimal use of cues by the person and inconsistent use of cues. These factors have been quantified by the lens model equation [6] [7] and have been extensively studied. [8]
Uncertainty is fundamental to Brunswik's theory. In Brunswik's original model (Figure 3) "stray causes" and "stray effects" represent uncertainty on both sides of the model. The "Zones of ambiguity" (Figure 1) also include uncertainty.
In the environment, the cues are only probabilistically related to the criterion. Hence, perfect judgment is impossible. The relation between the cues and the judgment is also probabilistic because people are not perfectly consistent when making judgments. [24] [25]
For most tasks, including clinical inference, there is no single cue that perfectly predicts the criterion (Ye). Instead, prediction is mediated by multiple cues (Xi), each with some predictive validity of the criterion ("ecological validity"). Moreover, the cues are often substitutable, so that equivalent levels of predictive validity often are possible using different ways of combining cues. For example, in clinical inference, different clinicians could have equivalent levels of achievement using different (substitutable) cue combinations. Nevertheless, as Brunswik [26] pointed out, the highest predictive validity ("probabilistic stabilization, achievement") is typically achieved by consistently using the cues with the highest ecological validity ("family hierarchy of cues"). This was observed in the clinical inference case described above: "Certain clinicians were found to be using invalid cues, others neglected the valid ones" [1] (p. 261).
The lens model represents Brunswik's key concepts of vicarious mediation and vicarious functioning. The left side of the lens model represents vicarious mediation—the structure of the task environment that allows various potentially substitutable ways of combining the cues to predict the criterion. The right side of the lens represents vicarious functioning—the different ways that people combine the cues when making judgments.
The existence of cue intercorrelations is central to Brunswik's concept of Representative design. Some judgment and decision-making studies neglect to represent the environment in which a judgment takes place. [27] [28] The lens model approach emphasizes the importance of environmental representation in research.
Another basic tenet of Brunswik's theory is the importance of an idiographic approach – separate analyses of each person before aggregating the results. [29] [30] This contrasts with the nomothetic approach that combines the responses of the participants in a study, thus averaging out individual differences. The lens model represents one or more judgments made by a single individual.
Brunswik argued that judgment is not wholly rational but involves elements of both perception and thinking, that is, it is "quasi-rational." [19] Quasi-rational thought involves elements of both intuition and analysis. This is not indirectly represented in the lens model because it is embedded in "Process detail" and "Stray effects" on the right side of Figure 3.
A major application of the lens model has been in the study of multiple cue probability learning. [31] The lens model has been applied to studies studying human judgment in many other domains including business, [32] education, [33] medicine, [34] [35] social psychology, [36] forecasting, [37] meteorology, [38] evaluation research, [39] [40] and cybersecurity. [41] See Karelaia and Hogarth (2008) [8] and Kaufmann and Athanasou (2009) [42] for reviews of lens model applications.
Hammond and his colleagues [2] [3] extended Brunswik's classical double-system lens model, to include single-system (one judge at a time), double system (two judges), triple-system (two judges and a criterion), and N-system (N-judges, with or without a criterion) cases (see Cooksey, [3] Chapter 2). These cases describe research designs as well as practical applications of the lens model. They have been used to study aesthetic and value judgments, [43] [44] interpersonal learning, [45] cognitive conflict, [46] [47] and social values. [48] For more information on these designs, see judgment analysis and the lens model equation.
Psychological statistics is application of formulas, theorems, numbers and laws to psychology. Statistical methods for psychology include development and application statistical theory and methods for modeling psychological data. These methods include psychometrics, factor analysis, experimental designs, and Bayesian statistics. The article also discusses journals in the same field.
Psychometrics is a field of study within psychology concerned with the theory and technique of measurement. Psychometrics generally covers specialized fields within psychology and education devoted to testing, measurement, assessment, and related activities. Psychometrics is concerned with the objective measurement of latent constructs that cannot be directly observed. Examples of latent constructs include intelligence, introversion, mental disorders, and educational achievement. The levels of individuals on nonobservable latent variables are inferred through mathematical modeling based on what is observed from individuals' responses to items on tests and scales.
Personality psychology is a branch of psychology that examines personality and its variation among individuals. It aims to show how people are individually different due to psychological forces. Its areas of focus include:
A heuristic or heuristic technique is any approach to problem solving that employs a pragmatic method that is not fully optimized, perfected, or rationalized, but is nevertheless "good enough" as an approximation or attribute substitution. Where finding an optimal solution is impossible or impractical, heuristic methods can be used to speed up the process of finding a satisfactory solution. Heuristics can be mental shortcuts that ease the cognitive load of making a decision.
Heuristic reasoning is often based on induction, or on analogy ... Induction is the process of discovering general laws ... Induction tries to find regularity and coherence ... Its most conspicuous instruments are generalization, specialization, analogy. [...] Heuristic discusses human behavior in the face of problems [... that have been] preserved in the wisdom of proverbs.
Validity is the main extent to which a concept, conclusion, or measurement is well-founded and likely corresponds accurately to the real world. The word "valid" is derived from the Latin validus, meaning strong. The validity of a measurement tool is the degree to which the tool measures what it claims to measure. Validity is based on the strength of a collection of different types of evidence described in greater detail below.
Construct validity concerns how well a set of indicators represent or reflect a concept that is not directly measurable. Construct validation is the accumulation of evidence to support the interpretation of what a measure reflects. Modern validity theory defines construct validity as the overarching concern of validity research, subsuming all other types of validity evidence such as content validity and criterion validity.
The recognition heuristic, originally termed the recognition principle, has been used as a model in the psychology of judgment and decision making and as a heuristic in artificial intelligence. The goal is to make inferences about a criterion that is not directly accessible to the decision maker, based on recognition retrieved from memory. This is possible if recognition of alternatives has relevance to the criterion. For two alternatives, the heuristic is defined as:
If one of two objects is recognized and the other is not, then infer that the recognized object has the higher value with respect to the criterion.
Ecological psychology is the scientific study of the relationship between perception and action, grounded in a direct realist approach. This school of thought is heavily influenced by the writings of Roger Barker and James J. Gibson and stands in contrast to the mainstream explanations of perception offered by cognitive psychology. Ecological psychology is primarily concerned with the interconnectedness of perception, action and dynamical systems. A key principle in this field is the rejection of the traditional separation between perception and action, emphasizing instead that they are inseparable and interdependent.
In the behavioral sciences, ecological validity is often used to refer to the judgment of whether a given study's variables and conclusions are sufficiently relevant to its population. Psychological studies are usually conducted in laboratories though the goal of these studies is to understand human behavior in the real-world. Ideally, an experiment would have generalizable results that predict behavior outside of the lab, thus having more ecological validity. Ecological validity can be considered a commentary on the relative strength of a study's implication(s) for policy, society, culture, etc.
In psychology, the take-the-best heuristic is a heuristic which decides between two alternatives by choosing based on the first cue that discriminates them, where cues are ordered by cue validity. In the original formulation, the cues were assumed to have binary values or have an unknown value. The logic of the heuristic is that it bases its choice on the best cue (reason) only and ignores the rest.
Cue validity is the conditional probability that an object falls in a particular category given a particular feature or cue. The term was popularized by Beach (1964), Reed (1972) and especially by Eleanor Rosch in her investigations of the acquisition of so-called basic categories.
Affect, in psychology, is the underlying experience of feeling, emotion, attachment, or mood. It encompasses a wide range of emotional states and can be positive or negative. Affect is a fundamental aspect of human experience and plays a central role in many psychological theories and studies. It can be understood as a combination of three components: emotion, mood, and affectivity. In psychology, the term affect is often used interchangeably with several related terms and concepts, though each term may have slightly different nuances. These terms encompass: emotion, feeling, mood, emotional state, sentiment, affective state, emotional response, affective reactivity, disposition. Researchers and psychologists may employ specific terms based on their focus and the context of their work.
Egon Brunswik Edler von Korompa was a psychologist who is known for his theory of probabilisitic functionalism and his proposition that representative design is essential in psychological research.
This entry will describe the proper narrow and technical meaning of "ecological validity" as proposed by Egon Brunswik as part of the Brunswik Lens Model, the relation of "ecological validity" in "representative design" of research, and will outline the common misuses of the "ecological validity." For a more detailed explanation, see Hammond (1998).
In perceptual psychology, a sensory cue is a statistic or signal that can be extracted from the sensory input by a perceiver, that indicates the state of some property of the world that the perceiver is interested in perceiving.
The need for cognition (NFC), in psychology, is a personality variable reflecting the extent to which individuals are inclined towards effortful cognitive activities.
Heuristics is the process by which humans use mental shortcuts to arrive at decisions. Heuristics are simple strategies that humans, animals, organizations, and even machines use to quickly form judgments, make decisions, and find solutions to complex problems. Often this involves focusing on the most relevant aspects of a problem or situation to formulate a solution. While heuristic processes are used to find the answers and solutions that are most likely to work or be correct, they are not always right or the most accurate. Judgments and decisions based on heuristics are simply good enough to satisfy a pressing need in situations of uncertainty, where information is incomplete. In that sense they can differ from answers given by logic and probability.
Intuitive statistics, or folk statistics, is the cognitive phenomenon where organisms use data to make generalizations and predictions about the world. This can be a small amount of sample data or training instances, which in turn contribute to inductive inferences about either population-level properties, future data, or both. Inferences can involve revising hypotheses, or beliefs, in light of probabilistic data that inform and motivate future predictions. The informal tendency for cognitive animals to intuitively generate statistical inferences, when formalized with certain axioms of probability theory, constitutes statistics as an academic discipline.
Werner W. Wittmann is a German psychologist, evaluation researcher and research methodologist.
Vicarious mediation is the potential level of substitutability in the task itself, the different potential ways that exist for achieving an outcome or performing a task successfully. For example, what is the substitutability of potential cues for accurate judgments about the size of objects in a visual field, particularly when all the cues are not available or are not perfect predictors of size? Similarly, what is the substitutability of potential behaviors to accomplish one’s goals when all actions may not be available or equally effective? The focus is on the task, the various potentially substitutable pathways mediating success in the task itself.