Proportional reduction in loss (PRL) is a general framework for developing and evaluating measures of the reliability of particular ways of making observations which are possibly subject to errors of all types.
[citation needed] Examples are the coefficient of determination and Goodman and Kruskal's lambda.
[3] It also provides a general way of developing measures for the reliability of qualitative data.
For example, this framework provides several possible measures that are applicable when a researcher wants to assess the consensus between judges who are asked to code a number of items into mutually exclusive qualitative categories.
[4] Measures of this latter type have been proposed by several researchers, including Perrault and Leigh in 1989.