Reggio teachers place a high value on their ability to improvise and respond to children's predisposition to enjoy the unexpected. Regardless of their origins, successful projects are those that generate a sufficient amount of interest and uncertainty to provoke children's creative thinking and problem-solving and are open to different avenues of exploration. Because curriculum decisions are based on developmental and sociocultural concerns, small groups of children of varying abilities and interests, including those with special needs, work together on projects.