Clinicians have always been aware of the importance of using clinical tests and measures that are valid and reliable – and avoiding those that are not. However, the choice of which tests and measures to use is often more a matter of personal preference, arising out of knowledge of the test‟s psychometric properties and one‟s experience with the test, rather than on a systematic critical appraisal of assessment tools. This paper outlines a proposal for how clinical assessments in the speech and language sciences can be critically appraised for the purpose of deciding whether they are likely to be informative in diagnosing individuals with communication disorders. QUADAS, a 14-item evidence-based critical appraisal tool (Whiting et al., 2003), originally designed to assess the quality of diagnostic accuracy studies used in systematic reviews in medicine, is presented with an example of how it can be applied in the field of communication disorders.