The process of diagnosis in counseling is most effective, however, when it is continuous, tentative, and testable. Because the process of diagnosis permeates and pervades the entire process of counseling, diagnosis is an ongoing process of continuous modification of our impressions and perceptions of clients.
A very apt description of this ongoing process was given by the Pepinskys (1954) when they characterized the diagnostic process as one of constructing a “hypothetical” client out of our limited and finite perceptions based on our observations of the client’s behavior. Since we never really have access to what goes one “inside” the client, the model that we construct, that is, our “hypothetical” client, is always just that. It always represents a partial, imperfect, and perhaps obsolete approximation of the actual, ever-changing, flesh-and-blood client whom we seek to help.
As the counselor observes carefully and systematically, these observations are organized and a set of inferences, guesses, or “clinical hunches” emerges. These inferences are organized into a picture or impression that constitutes the “hypothetical client.” It is this image of the hypothetical client that provides the actual basis for the counselor’s response. The counselor usually responds to the real, flesh-and-blood client as though he or she were like the hypothetical model that, in fact, exists only in the counselor’s mind.
Like all of us engaged in relationships with others, the counselor must constantly bear in mind that our impressions are forever tentative and must be kept open to revisions and additions born out of new observations and more credible inferences. As new observations are made and new inferences and hunches are formulated, the "hypothetical client" grows richer, more detailed, more complex, in a sense more fully clothed and filled out.
However, new observations and inferences tend to challenge those made earlier, so that the hypothetical model will have to be modified or even drastically changed. If the model is ever frozen, that is, viewed as complete, final, and perfected, we may shut out new information, thus making our model increasingly different from our real, flesh-and-blood client. If this happens, our responses are based on increasingly erroneous and obsolete perceptions.
Since the counselor operates from information provided by the hypothetical client, it is important to provide that model with as much credibility as possible. Even though we know that our impressions can never be final or foolproof, we can strengthen them by continually testing the predictions we make from them.
This process of hypothesis testing is the third characteristic of effective diagnostic processes. It is possible to frame our inferences, or "hunches," as testable propositions that can be refuted or supported in terms of the accuracy of the predictions which they generate.
In this way we can, to some extent, verify our impressions and inferences before we allow them to become part of our hypothetical client and, above all, before we act on them in response to our real client.
In order to be testable, hypotheses must be framed in operational terms. That is, our hypotheses need to be translated into predictions about the client that can be verified or proven false through our later observations of the client's behavior. Such predictions can be confirmed or rejected in a variety of ways—by observations made in subsequent interviews, by independent observation made outside of the counseling situation, by test results, or by the observations of other people in the client's environment.
One of the greatest dangers in the diagnostic process is that we will not take the trouble to test our impressions and inferences rigorously. Instead, we may lapse into the intellectually sloppy habit of taking everything at face value. Unless we consciously recognize the tentative nature of our inferences, we are unlikely to frame our hypotheses rigorously enough, so that the predictions we make on their basis will not generate enough negative evidence to disconfirm some of our most cherished hunches.
In this kind of diagnostic process counselors must incorporate the scientist into their professional identities. It is precisely this willingness to employ self-correcting methods to work with clients that distinguishes the professional counselor from all of the other well-intentioned, but often naive and unsystematic would-be-helpers in the community.
In systems terms this process of hypothesis-testing allows the counselor to obtain feedback about the quality of his or her own thinking and thus to function as an "open system." When we follow diagnostic procedures that are continuous, tentative and testable, we reduce many of the dangers of using formal diagnostic constructs and frameworks. For example, we can consider our tentative assignment of a client to the "striving" category of the model of human effectiveness described earlier as a hypothesis to be tested, rather than as a fact to be uncritically accepted. We can frame a set of predictions about the client's behavior that are drawn from characteristics included in the definition of the category and then continuously test these predictors to determine their accuracy.
Donald H. Blocher. (1987). The Professional Counselor. New York: Macmillan Publishing