Very easy to translate, but only an expert would understand the precise technical meaning of this term from behavioural psychology. For example "being worried" is not an observable behaviour, while "being tearful" in the literal sense of lacrimating is. I think that you can only translate accurately with certainty if you fully understand the meanings of the terms.
http://www.simplypsychology.org/behaviorism.html Behaviorism is primarily concerned with observable behavior, as opposed to internal events like thinking and emotion. Observable (i.e. external) behavior can be objectively and scientifically measured. Internal events, such as thinking should be explained through behavioral terms (or eliminated altogether).