A prominent example of modifying a research design to reduce participant risk is Jerry Burger's $2009$ replication of Stanley Milgram's obedience study. To avoid the severe psychological stress caused by the original experiment, Burger stopped the procedure just before participants administered a $150$-volt shock, rather than allowing them to proceed to the $450$-volt maximum. This modification was effective because past data showed that participants who reached $150$ volts typically continued to the maximum, allowing Burger to validly compare obedience rates while minimizing harm.