A Measure of Ordinal Consensus

A common measuring device in sociology consists of a question or statement which provides a series of ordered options, from which the respondent chooses one most appropriate for his response. The options may represent for example, degrees of agreement or disagreement with an opinion statement, degrees of obligation to perform a given task, etc. While the most typical use of such items, singly or combined to form scales, is to describe the attitudes, opinions or values of individuals and collectivities, it is at times desirable to know to what extent a set of respondents concur in their choices, i.e., to what extent there is consensus.