Congratulations to the ISPOR PRO Mixed Modes Good Research Practices Task Force [1] for tackling a challenging question that many patient-reported outcome (PRO) researchers have pondered either publicly or privately as they review PRO results tables based on data collected through a combination of data collection methods: “Would these results and the study conclusions be different if the same mode had been employed?” The report’s general recommendation to “Just say no!” to mixing modes within a single study (or set of studies that may be pooled) is good advice and, if followed, will save many headaches and resources.