Article Photos: Smart machines provide tough competition for middle-class workers 1/3

This combination of Associated Press file photos shows, left, passengers checking-in at an American Airlines ticketing counter in 2011, in Dallas, and right, a row of self-check-in kiosks in 2012, in Seattle. Many middle-class workers have lost jobs because powerful software and computerized machines are doing tasks that only humans could do before. <strong> - AP</strong>