When students are praised for effort rather than ability, they are often more willing to try challenging tasks than children who believe their performance is based on innate ability. Students who are praised unexpectedly for doing a task have been shown to be more likely to perform the task again later. However, when a reward is expected, children may still complete a task to get it, but might not do it again when the reward is not available.
When students are frequently praised for their answers, some research shows they tend to respond less frequently and with less confidence. Students who become accustomed to consistent praise may come to depend on teacher praise to be sure of their answers. Students who receive ability-based praise may come to view themselves as "smart" or "good at math" and avoid tasks where they might not succeed. Avoiding challenging tasks causes students to miss out on valuable learning experiences.
Many teachers praise student behavior as a means of getting other students to do the same thing. This can backfire with some students, who do not want to be held up as an example among their peers and might avoid being the first to comply next time. Motivating good behavior with praise can have the same pitfalls as using it to motivate student work, in that students come to expect praise for all their behavior and might only follow classroom rules when the teacher is available to praise them.
Because there is only one teacher in a classroom of 25 or more students, verbal praise is only one piece of the puzzle for motivating students. Clear expectations for classroom behavior is more effective than praise for gaining compliance. Teachers can give effective feedback by making it specific, honest and related to the student's effort, rather than her natural ability. This helps children learn that careful work and attention will result in positive outcomes in the classroom. Giving praise at unexpected times, immediately after the praised behavior, also makes it more effective.