Ecological Validity

Definition

Ecological validity is the extent to which research findings would generalize to settings typical of everyday life. As such, ecological validity is a particular form of external validity. Whereas external validity refers to the overall extent to which findings generalize across people, places, and time, ecological validity refers more specifically to the extent to which findings generalize to the settings and people common in today's society.

Background and Distinctions

Validity has many faces, including internal validity (accurate claims about cause), construct validity (accurate claims about the nature of variables), and external validity (accurate claims about how processes and findings generalize across people, places, and time). Ecological validity is one aspect of external validity in which researchers ask whether research results represent what happens in everyday life. More specifically, ecological validity addresses whether an effect has been shown to operate in conditions that occur often for people in the population of interest.

In this regard, ecological validity is closely related to the concept of mundane realism. Experimental tasks are said to have mundane realism when they closely resemble activities that are common in natural settings. For example, activities in an experiment might be realistic in this mundane way when participants are asked to read a newspaper story about an obscure issue in a foreign country. This study might be considered as having a great deal of mundane realism because it uses activities common in everyday life (reading a newspaper). Yet the study may also be considered as lacking in experimental realism (the extent to which the activities are meaningful and have an impact on participants) if the topic of the newspaper article is uninteresting and fails to engage participants.

Ecological validity does not simply reflect an absence of experimental realism, because there are certainly many engaging and influential activities that form core aspects of everyday life. In fact, one might distinguish between mundane realism and ecological validity by noting that, in the real world, people would be relatively unlikely to spend time reading a newspaper article about a topic about which they know and care very little. Thus, although newspaper reading itself seems to reflect everyday activities quite well (mundane realism), the use of that activity in the experimental setting may diverge from the ways and reasons people typically read newspapers. That is, findings based on the use of this activity may lack ecological validity.

In this sense, ecological validity is also related to psychological realism (the extent to which the psychological processes operating in an experiment also occur in everyday life). When discussing psychological realism, it is important to distinguish between the specific activities and materials used in a study (mundane realism), the likely impact of the activities and materials (experimental realism), and the types of psychological processes that participants use to complete the activities in the study. Even if the activities in a study bear little resemblance to real-world activities (low mundane realism) and have relatively little impact on participants (low experimental realism), the thought processes that participants use in the study may be quite common in the real world (high psychological realism). For example, if a study involves judging words as quickly as possible as they appear on a computer screen, this would not be a typical activity in everyday life, and the words may not create strong reactions in research participants. However, if the words are activating concepts that then help people to quickly comprehend the next word on the screen, this may demonstrate a psychological process (concept activation) that is extremely common in everyday life.

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