Society for Industrial and Organizational PsychologySociety for Industrial and Organizational Psychology (SIOP) advocates the scientist-practitioner model in the application of psychology to all types of organizational and workplace settings, such as manufacturing, commercial enterprises, labor unions, and public agencies. Members work in several fields within I-O psychology, such as testing/assessment, leadership development, staffing, management, teams, compensation, workplace safety, diversity, and work-life balance.