Because other research has indicated that nonverbal cues can be laden with emotion, and even be important indicators of deception, understanding the use of nonverbal cues in response to certain questions by therapists can give those therapists an important point of reference in evaluating responses. Unfortunately, despite some significance in the statistical findings of Hill and Stephany (1990), there are complications and limitations to the usefulness of this research study. In theory, this could be an incredibly useful research study because it could provide therapists with a new, statistically proven, tool for evaluating the responses of clients and improving their therapeutic methods. Unfortunately, even Hill and Stephany (1990) admit that they had difficulty reconciling their findings with the research already extant or hypothesized in the relevant literature. For example, previous research has indicated that less controllable nonverbal cues such as leg movements or posture shifts should be more significant than those that are easier to control such as head movements or speech hesitations. In fact, this study found the exact opposite to be true, calling into question the overall validity of the findings. What's more, the relatively small sample size used by the researchers in this instance may have produced results and conclusions that would be untenable in a larger study. If this is the case, it would require a much more extensive study of the same nature to produce any truly valuable results.

Perhaps most damning, however, is the unfortunate fact that nonverbal cues are largely idiosyncratic and cannot...

For instance, a slight smile by one client could indicate happiness or mild agreement. From a different client, that same smile might suggest purposeful deception or misleading responses. Even if this study could find that certain nonverbal cues are significant, there would be no way to attach substantive meanings to those cues. At best therapists would be confronted with a tool that could give them an inkling that there was more to a client's responses, though it would be all but impossible to ever determine exactly what the nature of that hidden message could be. That Hill and Stephany (1990) also admitted that their research did not correct for any sociocultural variations in nonverbal cue responses only further limits the usefulness of this study for therapists. At best, this research could provide a useful starting point for other researchers who wish to probe a similar question and evaluate the implications of nonverbal communication in a therapy setting.
In the end, Hill and Stephany's (1990) "Relation of Nonverbal Behavior to Client Reactions" is a well planned out research study of the importance of nonverbal communication in a therapy session. The aim of the study is significant enough, and the methodology quite solid. However, numerous other limitations in the design and nature of the study, already touched upon, limit the overall usefulness of this research for both practitioners and researchers.