[5] He started his professional career in the development sector as an active intervener in the processes of social change in rural areas of India.

[6] He founded the Society for Participatory Research in Asia PRIA as a vehicle to strengthen learning opportunities at the grassroots level and to articulate knowledge for wider social influence, in 1982.

He developed participatory training, monitoring, and evaluation methodologies supported by and to enhance adult learning and community knowledge.

[5][6] His contributions revolve around issues of participatory research, advocating for people centered development, policy reform and networking in India, South-Asia and beyond.

[19] An expert on women's empowerment, Farrell was running a series of workshops on "gender mainstreaming" in Afghanistan for locals and government officials.