Head start/preschool teachers Preschool teachers             Teach and care for children, usually ages  three to five, and help them get ready for elementary school

Research has established that preschool education can produce substantial gains in children's learning and development (Barnett, 2002), but researchers disagree about whether such gains are permanent. Most research on early education has focused on its effects on the IQ scores of economically disadvantaged children and has found few preschool programs that have produced lasting IQ score gains (Barnett, 1998). Even the more effective programs tend to show positive results in the short rather than long term.