Some common shortcomings in movement behaviour analysis methodology methodology

As outlined in Chapter 1, despite the fact that there is a long tradition and a broad scientific interest, movement behaviour research has, thus far, not been established as a scientific discipline on its own. Apart from the fact that the di-aspora of movement behaviour across many different disciplines is an obstacle for developing a common body on knowledge, this situation also has negative consequences for the standard of movement behaviour research methodology.

Common methodological standards have been developed only rudimentary, a condition which negatively influences the quality of research. Foremost, it is striking to find that still many researchers develop their own coding system. Of-ten, these researchers do not have a scientific background that is related to body movement and they are not trained in movement analysis. Not surprisingly, they are not aware of the fact that the analysis of movement behaviour is just as com-plex as, for instance, the analysis of an electroencephalogram. A number of typical methodological shortcomings are listed below:

(i) Precipitate interpretation

A precise analysis of the movement behaviour per se based on the visual ap-pearance of the movement is seldom conducted. Instead, researchers quickly turn to interpreting the movement behaviour with regard to the function of their research interest, e.g. emotion. However, a number of experiments on the inter-pretation of movement behaviour evidence that this approach is highly problem-atic. These interpretation experiments unanimously reveal that naïve raters may agree in their interpretations on movement behaviour, e.g. judging a person’s dominance by observing his / her gait, these judgements, however, are wrong with regard to an objective measure (Eisenberg and Reichline, 1939; Mason, 1957; Wallbott, 1989). Therefore, Frijda (1965) proposed that understanding the laws of the assessment of an expression is at least as important as the laws how meaning is expressed (for a detailed discussion see Chapter 12).

(ii) Simple but not valid values

Often, movement values are chosen just because they are simple to code. Such values might show a good objectivity and reliability, but they are not valid with regard to cognitive, emotional, and interactive functions. As an example, classi-fying hand movements with the two types 'spread fingers' versus 'closed fingers' will show a high objectivity and interrater reliability: However, the values psent entities of movement behaviour that are not particularly relevant with re-gard to cognitive, emotional, and interactive processes. As another example, counting the number of foot taps in a psychotherapy session is simple but the value foot tap is too unspecific and not valid with regard to psychotherapy out-come.

(iii) Broad values

The movement values are too broad. Thus, they contain different movement en-tities that are associated with different cognitive, emotional, and interactive functions. An example is the value free movement, which is defined as "any mo-tion of the limb which did not result in touching of the body or coming to rest”

(Kimura, 1973, p. 46). Recent research has demonstrated that this value com-prises too many hand movements that are associated with different neuropsy-chological functions (Lausberg & Kita, 2003; Lausberg et al., 2007). Studies using more fine-grained values have even produced results that contradict those of the studies applying the free movement value. Thus, the scientific profit when conducting movement analysis with such broad values is limited.

(iv) Confounded values

Researchers who are trained in a non-movement scientific discipline typically pursue movement behaviour research more or less intensively as part of their own discipline. Accordingly, they analyze movement behaviour as a by-product of the core subject of their own scientific discipline. As a consequence, method-ologically, they describe and interpret movement behaviour with the methods and terminology that they employ in their primary scientific discipline. As an example, linguists may use linguistic criteria to analyze movement behaviour.

As a consequence, the specific properties of movement behaviour per se are not considered. Moreover, often the movement values these researchers design, are confounded with values of their primary scientific discipline. As an example, the factors "retardation" and "agitation" reported by Ulrich and Harms (1985) for depressive patients are confounded with psychopathological symptoms.

(v) Insufficiently operationalized values

Other researchers create more complex movement values but they operationalize them insufficiently. The imprecise definitions of the values entail an insufficient objectivity, and a lack of reliability and validity.

Furthermore, vague value definitions render it difficult to compare study re-sults. Often it is not evident from the description given in a paper, what kind of movement had actually been coded. Hence, it is not possible to replicate the analysis and to confirm or to disapprove the results. As an example, the apparent contradictions between different research studies on the relation of aphasia and gesture are essentially caused by the fact that different researchers had investi-gated movement values that were termed similarly but actually included differ-ent types of movemdiffer-ents (for an elaboration on this topic, see Lott, 1999). Con-trolling the quality of the value operationalization by examining interrater agreement, i.e., when two independent observers agree on the value of a move-ment unit, is a rather recent developmove-ment in movemove-ment behaviour research, and it is still not yet fully established as a standard method.

(vi) No rater training

Researchers who do not appreciate movement analysis as a skill consequently employ naïve raters to assess movement behaviour. However, movement values that are valid with regard to complex cognitive, emotional, and interactive proc-esses are complex, too. In other words, a simple movement value such as a foot tap is not valid with regard to a complex phenomenon such as psychotherapy outcome. Therefore, the coding of movement values that are relevant with re-gard to cognitive, emotional, and interactive processes requires a substantial training. It is comparable to the training that a cardiologist needs to auscultate and classify heart sounds. In fact, a rater's observation skill for the other person's

movement behaviour correlates with the quality of the self-assessment of her/his own movement behaviour that, in turn, improves with her/his own movement experience (Wolff, 1932; Calvo-Merino et al., 2005; Cross et al., 2008) (for a detailed discussion of the impact of rater training, see Chapter 12).