Nearly one-fifth of the world’s adult population – 771 million adults – lack the basic literacy skills vital to improve their livelihoods, according to the EFA Global Monitoring Report released in November 2005. But where does this number come from? Does it include migrant workers, nomads or refugees? And how accurate is it? The Report makes cross-national comparison of literacy using data compiled by the UNESCO Institute for Statistics (UIS). About two-thirds of the country statistics come from nationally-reported figures based on national censuses or surveys.