Dr Frank Hardman, Fay Smith and Kate Wall of Newcastle University studied 70 teachers in literacy-hour lessons to assess the impact of "interactive teaching".
Interactive teaching is about giving pupils time to think before answering questions, and asking them to clarify and elaborate on their ideas to the class.
The policy is part of the national literacy strategy.
But teachers were also warned not to allow increased pupil contributions to interfere with the pace of the lesson. And faced with this dilemma, the study found teachers tend to rattle off questions which require short answers at a rate of almost one a minute.
Dr Hardman told the European Educational Research Association conference that teachers needed better in-service training.