Applied behavior analysis (ABA), also referred to as behavioral engineering, is a behavior modification system based on the principles of respondent and operant conditioning. ABA is the applied form of behavior analysis; the other two are: radical behaviorism and experimental analysis of behavior, which focuses on basic experimental research.
'Be careful, they are watching you': Tibet is silent as Dalai Lama turns 90
The BBC speaks to Tibetans in Aba, which has long been at the heart of resistance to Chinese rule.
BBC News