Like everyone who lost a loved one on 9/11 Steve and Liz Alderman were devastated when their 25-year-old son, Peter, was killed in the World Trade Center attack. Like many , they chose to honour their son's memory by creating a foundation in his name.

Of the 303 non-profit organisations launched in response to 9/11, only 27 were still operating five years later, according to a study by the NonProfit Times. What has kept the Peter C. Alderman Foundation going is his parents' focus on maximising the impact of their foundation through rigorous analysis. In the words of Peter's father, Steve: "We will abandon anything that doesn't work."