Technology Counts

Until now, most research on technology's effectiveness has taken the form of small case studies, some of which examined just a classroom or two at a time. Though several of these studies found evidence that technology can improve student achievement, the findings don't necessarily apply to other classrooms where teachers are less motivated or knowledgeable about computers.

A new national study on the effectiveness of teaching with technology appears to confirm what many educators have suspected for years: Computers can raise student achievement, but they can also do more harm than good when...