Audrey Holland (1982) compared test scores to observers' ratings of conversational communicative success in people with aphasia (PWA). This springboarded a body of evidence employing observers to rate discourse. We review the utility of those ratings for assessing PWA's communication success. A traditional literature review identified 16 articles involving naive or trained raters assessing PWAs' communicative success across discourse genres. Another 10 articles reported ratings over time. Collectively, these studies evaluated 349 PWAs. Four studies utilized observers to rate the success of PWA's conversations. Eight studies that reported observers' ratings on other discourse genres found that multimodal communication and facilitative contexts improved success, and ratings of informativeness and comfort related to objective discourse analysis measures. Nine of 10 studies examining treatment effects found that communicative success ratings captured improvements. Observers' ratings provide social validity by reliably assessing the discourse-level communicative success of PWA. Ratings correlated with standardized diagnostic and objective discourse metrics but provided a window into factors that affect communicative success, including the degree to which communication is interactive, multimodal, and contextual. Integrating observers' ratings of discourse success at pretreatment may help identify supports or barriers to successful communication, facilitate individualization of treatments, and offer social validity of change.
