A functionally illiterate adult can read, write, and do basic mathematics calculations, but not well enough to fulfil all the tasks society expects of him. He lacks the skills required to function effectively in his community. He may have received little or no formal education, or his formal education may have been inadequate to the point that he remained functionally illiterate.
An 1997 OECD survey of its 12 member countries stated that, depending on the country, between 25% and 75% of the respondents aged 16 to 65 did not have a literacy level considered 'a suitable minimum skill level for coping with the demands of modern life and work.' Sweden had the highest functionally literacy level, Poland the lowest. There was no statistically significant difference among Australia, Belgium, Canada, Germany, Ireland, Netherlands, New Zealand, Switzerland, UK, and the USA.