Q Methodology (Q) is a complete methodology which involves technique (sorting), method (factor analysis), philosophy, ontology, and epistemology.  Q reveals and describes divergent views in a group as well as consensus. Q was created by William Stephenson (1902-1989) who possessed PhDs in physics (1926) and psychology (1929) and studied psychometrics with Charles Spearman, the creator of the factor analysis.

Stephenson, 1953, Study of Behaviour, p. 1

“Our concern, however, is not to be with Q-technique alone, or even principally. Rather, it is with a challenge to psychology, in certain of its aspects, to put its house in scientific order. We are to consider a methodology to serve this purpose.  We call it “Q-methodology.” This is a set of statistical, philosophy-of-science, and psychological principles which, we believe, is such as is demanded by the present scientific situation in the psychological and social sciences.”

Brown, 1986, p.58

“Fundamentally, Q Methodology provides a foundation for the systematic study of subjectivity, and it is this central feature which recommends it to persons interested in qualitative aspects of human behavior . Only subjective opinions are at issue in Q, and although they are typically unprovable, they can nevertheless be shown to have structure and form, and it is the task of Q-technique to make the form manifest for purposes of observation and study”

Introduction to Q Methodology