Lectures are essentially spoken

The specific reasons for the effectiveness of lectures which I wish to highlight here, are that they are essentially a form of spoken communication which is delivered to an audience by an actually-present and visible person. A lecture therefore constitutes a formally-structured social event which fits human nature and artificially manipulates human psychology to improve learning. Furthermore, educational lectures are given in ‘courses’ (not one-off lectures), which enable the audience to develop a relationship of trust with the lecturer.

It is easy for educated people in advanced societies to forget that literacy and solitude are both relatively-recent cultural artefacts. In the hunter-gatherer societies in which our (neuro-anatomically identical) ancestors dwelled for many tens of thousands of years, information was communicated mainly by direct speech and individuals were almost never alone; on the contrary being continually surrounded by people they knew very well. By contrast all communication technologies – whether reading a book, audio-visual media, or a computer monitor – are artificial and contrived and studying alone is a difficult skill with widely varying levels of attainment. This is probably the major reason why so many people find it easier to learn from a spoken lecture and in groups rather than alone.

But attending a course of lectures requires a long term commitment to be in the necessary place at the proper time. If you are not present and listening, you will not obtain the advantage of attending a lecture and will have to make-do with solitary personal study. Students may miss lectures through no fault of their own, as well as for less admirable reasons. This is undeniably inconvenient, but it is intrinsic to the medium. Only if the lectures are sub-optimal can students miss them without incurring some disadvantage.

Therefore, when a lecture course is the focus of teaching care should be taken not to sacrifice the essence of lectures by confusing students over the core learning activity which is expected of them. In lecture based course, students should understand that one major expectation is that they are required to attend lectures. Because the main medium of communication in a lecture is the spoken word, what is spoken should be regarded as the essence. The only way to make lecture attendance unimportant to learning is to diminish the effectiveness of the lecture to the point that the lecture is so mediocre that it makes little difference whether students have experienced it or not.

It is tempting to try and ameliorate the disadvantages to students who cannot, or prefer not to, attend lectures; by providing identical or more-detailed material as handout – perhaps distributed by the internet. Once handouts are established, it is tempting to distribute them in advance of spoken lectures. But both of these temptations should be resisted. In order to make the most of their natural strengths, lectures need to maintain their proper focus on speaking as the primary form of communication.

The primacy of the spoken word may explain my strong impression that ‘lecture notes’ are a much more effective way of recording information than texts (such as hand-outs) which have been prepared by the lecturer. This is because lecture notes recognize the primacy of the spoken word. A students’ own written summary of a lecture they have heard also seems to be more readily remembered than hand-outs. One important factor is that lecture note-taking has the advantage of encouraging 'deep processing' forms of memorizing, by imposing a need for students to understand, abbreviate and re-structure the information in the course of recording it. Indeed, it is the taking of lecture notes which is a key factor in converting the potentially-passive experience of listening to a lecture into the active experience of learning from a lecture.

Lecture notes also avoid the undermining effect of hand-outs. It is hard to exaggerate the extent to which hand-outs can damage the effectiveness of a lecture. A lecture is compelling in part because it is here-and-now, the student must concentrate, listen, understand – and these activities cannot be put off until later. The intensity of a lecture depends on this necessity for the student to focus. The student must record the lecture in their notes, and they must do it now – lecture notes cannot be put off until later. But the existence of hand-outs or transcriptions usurps this evanescent reality by imposing an unchanging abstraction. A handout stands-between the student and the real-time lecture in the same way that a video-camera stands between a tourist and landscape they are standing in. To see a lecture through the lens of a hand-out is as impoverished a perspective as seeing the Alps through the viewfinder of a camera.

Lecture notes therefore do not support lectures so much as interfere with them – and ‘interference’ is a fairly precise term for the interaction of two similar phenomena to the disadvantage of both. Interference can best be avoided when the written material that supports a lecture is differently-structured from the lecture itself. For example, reading a good textbook after a lecture should be not just reinforce the same facts in the same order, nor even just add some extra facts, but should offer a significantly different structuring of the facts. In this case, the written material will deepen the knowledge obtained from lectures without damaging the here-and-now focus or memorability of lectures.

There are several other several implications. Lecture teaching methods should not allow verbal information to become subordinated to ‘visual aids’, although it is another temptation to ‘spice up’ the lecture with attention-grabbing graphics. The primary visual aid should the lecturer him- or her-self, especially the lecturers face, in particular the lecturers eye contact. A lecture which takes place in the dark, where a disembodied voice intones sentences while slides are shown, can hardly be described as a lecture at all because it lacks the basis of a social event. A slide-based lecture in the dark is more like visiting the cinema. Indeed, unless carefully used, technological visual aids can be a significant distraction from the conceptual basis of a lecture.

My feeling is that, on the whole, it is best for lecturers to avoid complex visual material, unless this is unavoidable; because although impressive visuals are often entertaining, they are also usually distracting, and may undermine the educational purpose. For example, audio-visual material (TV, video, animations etc) are such compelling stimuli that they can easily break the conceptual thread of spoken discourse. Switching back and forth between audio-visual technology and the spoken voice involves a cognitive change of gear which is hard for students to accomplish.

In this respect, public lectures and television documentaries are a bad model. This is because these one-off presentations are not trying to educate their audience except in the most vague and general sense – in fact they are mainly trying to grab and hold the audience’s attention. A one-off lecture is an end in itself: the audience is not expected to understand or remember what has been said.

But an educational lecture is a means to an end, which is learning, and methods to attracts and sustain audience attention should be subordinated to that over-arching educational imperative.