[বাংলা] 85% নিয়ম

# The 85% Rule: Why Getting Everything Right (Or Wrong) Kills Learning [Bengali content summary] Psychologist Robert Björk's research demonstrates learning is optimized at 85% accuracy. Material learned at this level is retained 50-70% longer than at 95%. Too easy (95%) and brain ignores it. Too hard (55%) and frustration kills engagement. At 85%, learners experience "desirable difficulty" — challenging but achievable. Error detection activates dopamine. Neuroimaging shows prefrontal cortex fully engaged. Amal's HLR adaptive system continuously monitors accuracy and adjusts difficulty, maintaining each child in this optimal 85% learning zone for maximum effectiveness.