Robert F. Bales

Robert Freed Bales (March 9, 1916 – June 16, 2004) was an American social psychologist.

Bales then became a professor at Harvard,[2] working in the university's Laboratory of Human Relations.

The observer is supposed to be well trained on the variables they are categorizing and they should be able to do it effortlessly; however, human raters bring with them their own preconceived schemas and heuristics.

To circumvent this pitfall, Bales’ method makes use of multiple observers and an inter-rater reliability is then derived from both raters’ produced data.

The unit of measure is the smallest discriminable segment of verbal or nonverbal behavior the observer can differentiate and classify.

[6] In 2016, the group honoured the centenary of Bales' birth by publishing excerpts from a video interview which he gave in 1996.