16. Transmissive Lectures: Learning by Listening

16.3. What Does Research Tell Us About the Effectiveness of Lectures?

Whatever you may think of Samuel Johnson’s opinion, there has indeed been a great deal of research into the effectiveness of lectures, going back to the 1960s, and continued through until today. The most authoritative analysis of the research on the effectiveness of lectures remains Bligh’s (2000). He summarized a wide range of meta-analyses and studies of the effectiveness of lectures compared with other teaching methods and found consistent results:

  • The lecture is as effective as other methods for transmitting information (the corollary of the course is that other methods – such as video, reading, independent study, or Wikipedia – are just as effective as lecturing for transmitting information).
  • Most lectures are not as effective as a discussion for promoting thought.
  • Lectures are generally ineffective for changing attitudes or values or for inspiring interest in a subject.
  • Lectures are relatively ineffective for teaching behavioural skills.

Bligh also examined research on student attention, on memorizing, and on motivation, and concluded (p.56):

‘We see evidence… once again to suppose that lectures should not be longer than twenty to thirty minutes – at least without techniques to vary stimulation.‘

These research studies have shown that in order to understand, analyze, apply, and commit information to long-term memory, the learner must actively engage with the material. In order for a lecture to be effective, it must include activities that compel the student to mentally manipulate the information. Many lecturers, of course, do this, by stopping and asking for comments or questions throughout the lecture – but many do not.

Again, although these findings have been available for a long time, and YouTube videos now last approximately eight minutes and TED talk 20 minutes at a maximum, teaching in many educational institutions is still organized around a standard 50-minute lecture session or longer, with, if students are lucky, a few minutes in the end for questions or discussion. There are two important conclusions from the research:

  • Even for the sole purpose for which lectures may be effective – the transmission of information – the 50-minute lecture needs to be well organized, with frequent opportunities for student questions and discussion (Bligh provides excellent suggestions on how to do this in his book);
  • For all other important learning activities, such as developing critical thinking, deep understanding, and application of knowledge – the kind of skills needed in a digital age – lectures are ineffective. Other forms of teaching and learning – such as opportunities for discussion and student activities – are necessary.