In 2000, after experiencing microaggressions firsthand, Dr. Ishiyama developed the A.R.T (Anti-discrimination Response Training) Program, now in use in schools and organizations across North America. The A.R.T. model describes four levels of witnessing: disengagement or “dis-witnessing”, passive witnessing, active witnessing and ethical witnessing that includes social action and activism, including educating others about social justice issues and the importance of breaking the silence and engaging in active witnessing.