To date, evaluations of participative ergonomics (PE) interventions have shown mixed results. In a multiple case study of four worksites in different companies, Dr. Wells' team examined process, implementation and effects of PE interventions. This study was based on fieldwork and interviews with 90 people. The team was able to introduce 10 to 21 changes over 10 to 20 months, despite some challenges. This plenary describes the research, which ultimately showed limited effects of PE interventions, and potential reasons that may account for this.