Q Methodology defines the distinctive set of psychometric and operational principles which, when combined with specialized statistical applications of correlational and factor-analysis techniques, provide researchers with a systematic and rigorously quantitative means for examining human subjectivity. Based on the premise that subjectivity is communicable and advanced from self-reference, the methods central concern is to ensure that self-reference is preserved and not compromised or confused by external investigation. The authors outline the appropriate principles, techniques and procedures which advance this goal, including data gathering, statistics and small-sample behavioural research.