The Perceived Awareness of the Research Hypothesis Scale: Assessing the influence of demand characteristics

The Perceived Awareness of the Research Hypothesis (PARH) scale is a 4-item quantitative self-report method for measuring the potential influence of demand characteristics in research situations.  It can be used to help to refute the idea that observed effects are due to demand characteristics.  The present article describes the PARH scale and discusses its advantages over other postexperimental feedback measures.  Different approaches to analysing PARH data are considered.  Finally, a survey of published research that has used the PARH scale shows that it has good internal reliability, and that it tends to show that research participants are not particularly aware of research hypotheses.