Most psychologists would probably describe our field as a science. It is notoriously difficult to say exactly what a "science" is, and I will not attempt to do so in detail here. In fact, as I will clarify below, there are reasons why it may be better not give the term "science" too exact a specification. Whatever the practice of science encompasses, however, it often includes at least some of the following: collecting observations under controlled conditions, testing hypotheses against these observations, formulating theories that are supported by the observations that are collected, and rejecting claims that are not supported by such observations in a predictable and reliable way.
Psychology's definition of itself as a science has been historically important. When the discipline of psychology was first founded in the late Nineteenth Century there were a number of widely accepted but questionable theories about human behavior. One example that is often given is phrenology, the idea that it is possible to predict a person's traits, abilities, and characteristics based on the shape of his or her head. The development of psychology as a rigorous science made it possible for researchers to discard theories like phrenology that might seem plausible to many people but that are not actually supported by systematic observations. The distinction between science and pseudoscience continues to be important today, for pseudoscientific claims about psychology are still frequently offered to the public in popular literature, credos, advice, and belief systems. For this reason, some authors (e.g., Lilienfeld et al., 2003) have written extensively about the problems of pseudoscience in psychology.
Despite the efforts of these authors, however, the distinction between science and pseudoscience turns out to be quite difficult to pin down in actual practice. There are many approaches to knowledge-gathering in the field of psychology, and it is not clear that all of these approaches can be unambiguously classified as either scientific or pseudoscientific. Many forms of psychotherapy fit this description. For example, humanistic psychotherapy involves procedures that are inherently inexact and that are aimed at bringing about changes that are not predictable in the usual scientific sense; however, this approach has produced knowledge that not only seems plausible but is also supported by a great deal of indirect scientific evidence (e.g., research indicating that people benefit from the use of humanistic techniques). Likewise, researchers who observe children playing or interacting in a natural social setting are not operating under controlled conditions, yet such uncontrolled observations can be extremely valuable in helping us to understand how children think and feel.
I am particularly interested in methods of understanding that fall into this ambiguous terrain - that is, methods that are not "scientific" in the stricter sense but that, when carried out properly, are capable of producing knowledge that is useful and valid. These methods are often referred to generically as "qualitative research," and they include techniques such as in-depth interviewing and naturalistic observation. One way of thinking about these techniques is that while they are not scientific in the strictest sense, they are scientific in a looser but more fundamental sense. Considered in this more fundamental sense, there are strong arguments that the results of qualitative research are valid, but in a very different way from those of tightly controlled "quantitative research." I will discuss this further on the next page, which concerns narrow and broad conceptions of science.