For the most part, Schleicher deflected his critics, PISA was not perfect, he conceded but it was better than any other option, and it got better each year. Like Bible salesman, he carried his Power point slides from country to country, mesmerizing audiences with animated scatter plots of PISA scores over time and across oceans His last slide read, in a continuousty scrolling ticker,"Without data,you are just another person with an opinion ...without data,you are just another person with an opinion