Descriptive contextualists seek to understand the complexity and richness of a whole event through a personal and aesthetic appreciation of its participants and features. This approach reveals a strong adherence to the root metaphor of contextualism and can be likened to the enterprise of history, in which stories of the past are constructed in an attempt to understand whole events. The knowledge constructed by the descriptive contextualist is personal, ephemeral, specific, and spatiotemporally restricted (Morris, 1993).Descriptive contextualists seek to understand the complexity and richness of a whole event through a personal and aesthetic appreciation of its participants and features. This approach reveals a strong adherence to the root metaphor of contextualism and can be likened to the enterprise of history, in which stories of the past are constructed in an attempt to understand whole events. The knowledge constructed by the descriptive contextualist is personal, ephemeral, specific, and spatiotemporally restricted (Morris, 1993). Like a historical narrative, it is knowledge that reflects an in-depth personal understanding of a particular event that occurred (or is occurring) at a particular time and place. Most forms of contextualism, including social constructionism, dramaturgy, hermeneutics, and narrative approaches, are instances of descriptive contextualism. Descriptive contextualism is strong in its adherence to contextualism’s root metaphor of the act-in-context, but suffers from several weaknesses. The analytic goals of descriptive contextualists are somewhat ill-defined, and it is difficult to determine when such goals gave been accomplished. This problem is openly acknowledged by many descriptive contextualists (e.g., LeCompte, Millroy, & Preissle, 1992, p. xv). In addition, a personal, holistic appreciation of a specific event and its context may or may not yield any practical knowledge or benefits (Hayes, 1993b).

Functional contextualists seek to predict and influence events using empirically-based concepts and rules (Biglan & Hayes, 1996; Hayes, 1993b; Gifford & Hayes, 1999). This approach reveals a strong adherence to contextualism’s extremely practical truth criterion and can be likened to the enterprise of science or engineering, in which general rules and principles are used to predict and influence events. Rules or theories that do not contribute to the achievement of one’s practical goals are ignored or rejected. Knowledge constructed by the functional contextualist is general, abstract, and spatiotemporally unrestricted (Morris, 1993). Like a scientific principle, it is knowledge that is likely to be applicable to all (or many) similar such events, regardless of time or place.

In psychology, functional contextualism has been developed explicitly as a philosophy of science (Biglan, 1995; Gifford & Hayes, 1999; Hayes, 1993b). Specifically, it has been offered as the philosophical basis of the field known as <em>behavior analysis</em>. From the perspective of functional contextualism, behavior analysis is a natural science of behavior that seeks "the development of an organized system of empirically-based verbal concepts and rules that allow behavioral phenomena to be predicted and influenced with precision, scope, and depth" (Biglan & Hayes, 1996, pp. 50-51). By studying the current and historical context in which behavior evolves, behavior analysts strive to develop analytic concepts and rules that are useful for predicting and changing psychological events in a variety of settings. These same concepts and rules can also be used to describe and interpret psychological phenomena for which prediction and influence are presently impractical or impossible (Biglan & Hayes, 1996; Skinner, 1974).

The behavior-analytic approach to studying psychological events can be described as selectionistic. Essentially, "behavior analysts think of the shaping of behavior as working in just the same way as the evolution of species" (Baum, 1994, p. 64). In biological evolution, contingencies of survival in a given environment select which genetic traits will persist in a species; in behavioral evolution, contingencies of reinforcement in a given context select which class of responses will persist (or be likely to occur) for an individual. Both the evolution of species and the evolution of behavior can be described as selection by consequences (Skinner, 1981), and the same process has also proven useful for interpreting the evolution of cultural practices (Biglan, 1995; Harris, 1979; Skinner, 1981). Indeed, behavior analysts consider human behavior to be "the joint product of (a) the contingencies of survival responsible for the natural selection of the species and (b) the contingencies of reinforcement responsible for the repertoires acquired by its members, including (c) the special contingencies maintained by an evolved social environment [a culture]" (Skinner, 1987, p. 55).  Contextualism and selectionism are closely related concepts, with selectionism being the causal mode inherent to contextual philosophy. Selectionism involves an emphasis on the role historical context and consequences play in shaping the form and function of the phenomenon of interest in the current setting—an emphasis that clearly reflects both the root metaphor and truth criterion of contextualism.

Implications of Functional Contextualism's Analytic Goal

Adopting the analytic goal of the prediction and influence of psychological events leads to several important ramifications for a psychological science. In fact, many of the distinctive characteristics of behavior analysis as a contextualistic science developed directly from this overarching goal. Behavior analysts’ rejection of mentalistic and cognitive explanations for behavior, emphasis on functional relations between behavior and environmental events, and preference for experimental research methods can all be linked to the field’s ultimate purpose. It is important to recognize that prediction and influence form a single goal, and functional contextualists thus value analyses that allow both the prediction and influence of psychological events. They seek to identify variables that "predict the event in question and would, if manipulated, affect the probability, incidence, or prevalence of the event" (Biglan, 1995, p. 34). Analyses which only allow the prediction of behavior, or which rely on variables that are not manipulable (at least in principle), are considered inadequate or incomplete.

Much of the research in psychology and education is based on the development of models that describe how hypothetical constructs and mediating cognitive (or neural) mechanisms determine overt behavior (Biglan & Hayes, 1996). These models generally attribute behavioral events to factors such as a person’s cognitive schema, information-processing mechanisms, brain activity, learning style, attitudes, expectations, knowledge constructions, emotions, thoughts, or feelings. Although these models can be quite accurate predictors of psychological events, they are not very helpful to those who also wish to know how to influence or change psychological events. When one type of psychological event is said to cause or explain another, with limited reference to the impact of environmental or historical variables, we are left with little knowledge of how to change or influence either type of psychological event. To change or influence the behavior or psychological events of another person, we must search for manipulable variables in the environment. Why? Because we are part of that other person’s environment. Anything we could possibly do to affect the performance of an individual, such as deliver psychotherapy or education, occurs in the environment of that individual—in the context of his or her behavior (Hayes & Brownstein, 1986).

In addition, the purported "causes" of behavior in cognitive and mentalistic models are themselves psychological events that require explanation. What caused the attitude, for example, and how can we change it? Once again, behavior analysts search for the answers to such questions in the environment, or—more specifically—in an individual’s lifelong history of interacting with his or her environment. Cognition and other internal events are interpreted by appealing to a person’s learning history, rather than assuming they are underlying processes causing and controlling overt behavior. To put this perspective in terms that may seem less controversial, behavior analysts simply believe that people learn how to think, reason, plan, construct meaning, problem-solve, and more through interactions with their natural, social, and cultural environments. Thus, behavior analysts attempt to identify aspects of the manipulable environment that influence the occurrence, incidence, prevalence, or probability of both private and overt psychological events.

The most effective strategy for identifying variables that both predict and influence behavior is controlled experimentation: events in the context of the behavior are manipulated in a systematic manner, and the resulting effects on the behavior’s occurrence are observed (Biglan, 1995; Hayes, 1993b). This orientation allows researchers to isolate which features of the context are functionally related to changes in the psychological event; purely descriptive or correlative research generally does not provide such knowledge. In behavior analysis, these procedures have traditionally involved the intensive study of individual organisms with time-series (or repeated measures) methodology (e.g., Barlow & Hersen, 1984; Sidman, 1960). While functional contextualists favor experimental techniques, they encourage the use of a diverse set of methodologies, provided that value is always measured against pragmatic goals (Biglan & Hayes, 1996). Group designs using between-subject comparisons can be employed effectively for the purposes of functional contextualism, for example, and even correlational or predictive research of the sort described above can provide clues about contextual variables that might impact behavior. Qualitative methodologies also have their uses in functional contextualism, but are not as effective as experimental procedures for testing the influence of environmental variables on behavior or for verifying the general utility of principles.