问题教学是教师在课堂教学中常用的一种教学方式,经过新课程改革的“实践一反思一再实践一再反思”的循环往复过程,课堂问题教学中的“问题”越来越少,大家已更多地关注于问题教学的有效性,即问题的针对性、科学性、效力性等方面的强弱程度。笔者以“浮力”一节课的教学片段为例,就发挥问题引导作用的有效性做一简析。片段一教师利用投影仪将“辽宁号”航空母舰的图片投射到大屏幕上,又播放了一段中国在南海举 Question teaching is a kind of teaching method commonly used by teachers in classroom teaching. After the new curriculum reform, “the practice of a reflection of repeated practice of reflection repeatedly” cycle of the process of teaching classroom problems “problem ” less and less , Everyone has paid more attention to the validity of problem teaching, that is, the degree of pertinence, scientificness and effectiveness of the problem. The author uses “buoyancy” a section of teaching as an example, give a brief analysis of the effectiveness of the problem guiding role. Fragment of a teacher using the projector will be “Liaoning No. ” aircraft carrier’s picture projected onto the big screen, and played a period of China in the South China Sea