I have made the experience that even the most excellent academics are often didactically mediocre lecturers. I also watched some of last years Nobel lectures and realised many laureates are actually not particularly good at teaching.
What is it that makes some lectures didactically effective and others not, regardless of how knowledgable the lecturer is?
Unless you put a lot of thought into your lectures, it's hard to adopt the mindset of a student who knows much less than you. You may take certain concepts for granted, and you've long forgotten how you learned them, or what originally confused you. At the time you learned them you were probably much more well-prepared than the average student, so common stumbling blocks for students were never issues for you.
This means there are a lot of professors who are good at giving talks (to people well-versed in their field), but poor at giving lectures (to people with little or no background).
What is it that makes delivering a good, clear, informative lecture so challenging?
It is challenging because learning is challenging. The things that one could easily convey to a very general audience simply by being clear and informative are by and large not the things (or certainly, not all the things) that one learns in university-level courses.
What makes a good lecturer is a great question, but a bit broad for a site like this. If you have a group of students / faculty colleagues, I highly recommend throwing this out to the group: break the question up into some directed subquestions, give everyone the questions, and then after a week or so meet to discuss their answers. I actually did something like this recently (the topic was "successful math talks"), and what ensued was entertaining and enlightening.
Here let me (still very superficially) try to address your observation that even Nobel Laureates need not be good lecturers. Again I will break this up into a few subquestions.
1) Do you expect a Nobel Laureate to be a better lecturer than a faculty member with a less exceptional research profile? Why or why not?
2) Do you think that Nobel Laureates would be especially good or bad at giving certain kinds of lectures, or lectures to certain kinds of audiences? Why?
I think everyone can get a turn at answering these questions. (Probably not here: the site is not designed for that.) Let me take a crack at the first one:
One can argue that Nobelists ought to be on average very good lecturers. First of all (contrary to what some people would like to think), intelligence and acumen in one domain is positively correlated with intelligence and acumen in another domain, and the correlation increases to perfect as the two domains converge. If you are a professor of X, then researching X and teaching X are your two main duties. They are different, but I can isolate a common variable. The best way to be a bad teacher is to have a poor understanding of your subject, and Nobelists must be the least at risk for that. The people who have not thoroughly mastered their field, especially at the level of coursework, are in my experience essentially never the people who are making the cutting edge breakthroughs.
Is it possible that when a true luminary gives a lecture, we evaluate them with that high standard in mind? I often tell the story of a colloquium I saw given by a Fields Medalist ("the mathematical equivalent of the Nobel Prize"). By chance I had read about his work, relatively casually, about a month before his lecture. I was profoundly disappointed by his lecture because it was merely clear and informative. The information he conveyed was almost exactly the information that I had read before. However, when I read about I found it incredibly exciting and impressive. In person he did not convey any of this: it was just a recitation of "In 1982, I proved this theorem; two years later I proved the following improvement". I felt afterwards that if for some (totally counterfactual) reason I had given the talk instead, I would have done a better job, because I would have been so enthusiastic. Mine is a sincere reaction, but you see that I was coming in with very high standards, and the idea that I could have done better ought to be construed as a description of the psychology of my reaction: taken literally, it seems rather unlikely.
One can also argue that it is not so surprising if Nobelists give lectures that are merely okay or actually not as good as what other faculty are doing. (Again it depends a lot on what kind of lecture we're talking about, which I am omitting for now.) Let's go back to what I said before: being a professor of X involves researching X and teaching X. Yes, these skills are positively correlated. But they also compete for our time. If you are a subject area expert with some teaching experience, then you can probably deliver a decent lecture on X with a moderate amount of preparation. But maybe moderate is more preparation than you want or feel that you can spare. If you don't prepare at all, then no matter how brilliant you are you are probably going to give a lecture which the audience will regard as being rough -- maybe too rough. If you want to give a better lecture then you probably have to prepare more. Now there are a lot of people in university environments who are spending much more time and thought preparing their lectures. It is not a zero-sum phenomenon because no one tells you exactly how many hours you should spend total in any given week. There are a lot of leading researchers who are clearly putting substantial time into their lectures. However, Nobelists are the extreme case: you are selecting people for which the community as a whole feels that their research is much more valuable than their teaching.
Taking these two things together: I would expect a Nobelist to give lectures that are excellent in some ways and below average in others. By the way, what makes a good lecture is a many-dimensional space, and many is the time that a friend and I have walked out of the same talk and discovered that one of us loved it and the other hated it. But if you're judging a talk by the types of things that go into undergraduate student evaluations: I think you're mixing together a lot of highs and lows and thus one should expect the results to be pretty much all over the place.
What makes giving a clear lecture so difficult? There are two components to giving an interesting and engaging lecture: content and delivery.
Does the speaker project, or mumble? Confidently walk about the room, or stay locked behind a lectern? Make eye contact, or spend more time looking at a white board than the audience? Read from a set of PowerPoint slides, or supplement them with pertinent material? Pepper their speech with ums and ahs, or speak as though the talk was more reheased? Presentation style is imporant. Two speakers can speak from the same script, with one keeping the audience riveted while the other puts them to sleep.
Most doctoral programs don't require a public speaking course – maybe they should? – and public speaking isn't taught in the physics lab, your advisor's office, or the department conference room. If you want to hone these skills, you'll need to do it on your own, join an outside organization such as Toastmasters, or participate in whatever faculty development opportunities are afforded at your institution.
This one is difficult for the lecturer, because much of the content is dictated by the course curriculum. We don't get to choose our topic, and speak about The Day I Was Rescued from the Well, or Three Secrets to Research Success. Instead, we are required to talk about Maxwell's equations, or orbital mechanics, or the logistics problems at the Battle of Wellington.
In the case of a Nobel laureate, this problem is compounded, because the speaker is often speaking about the culmination research to a general audience with little or no experience in the field. It can be challenging for a subject matter expert to distill vast knowledge and expertise into nuggets comprehensible for the layman; it's difficult to convey excitement to people with insufficient background knowledge to share that emotion. Advances in the field are made after years of study with tedious experimentation and observation. How long would you be able to retain interest talking about your dissertation research at a New Year's Eve party? Winning a Nobel Prize wouldn't make that any easier.
Whether it's a professor in front of the classroom, or a Nobel laureate in a university lecture hall, most talks seem to be about 50 minutes to an hour long: double the length of most sermons, and quadruple the length of most TED talks. That's a long time to hold the attention of an audience! Even accomplished speakers would find it difficult to engage an audience that long. That's why playwrights pen tales of love triangles, not mathematical proofs.
The classroom professor has an additional challenge in that the "audience" (i.e., the enrolled students) may not be all that motivated to learn, making it especially difficult to give a memorable performance while also ensuring valuable learning took place.
I've heard the following story, which seems relevant, but I can't find a source for it now. Someone asked Stanislaw Ulam for the rules for giving a good lecture. Ulam at first denied that such rules could exist, but the questioner persisted, and Ulam finally came up with the following two rules. (1) Have something to say. (2) If, by good fortune, you have two things to say, then say first the one and then the other, not both at once.
Violations of Ulam's rules account for surprisingly many of the occasions when I've left a lecture wishing I hadn't gone to it.
I think these are the most important properties:
There is large field of research dedicated to pedagogy, and the idea that you just are a good lecturer or not is as unfounded as saying that you are a good researcher or not. Everybody has some predispositions, but there is also a lot to learn from the existing literature, from colleagues, from past past experience, etc.
In the UK, the Higher Education Academy has developed the UK Professional Standards Framework (UKPSF), which is "a comprehensive set of professional standards and guidelines for HE providers and leaders". The rest of my answer is basically copied from the UKPSF.
The UKPSF defines three dimensions:
Areas of Activity
A1 Design and plan learning activities and/or programmes of study
A2 Teach and/or support learning
A3 Assess and give feedback to learners
A4 Develop effective learning environments and approaches to student support and guidance
A5 Engage in continuing professional development in subjects/disciplines and their pedagogy, incorporating research, scholarship and the evaluation of professional practices
Core Knowledge
K1 The subject material
K2 Appropriate methods for teaching, learning and assessing in the subject area and at the level of the academic programme
K3 How students learn, both generally and within their subject/ disciplinary area(s)
K4 The use and value of appropriate learning technologies
K5 Methods for evaluating the effectiveness of teaching
K6 The implications of quality assurance and quality enhancement for academic and professional practice with a particular focus on teaching
Professional Values
V1 Respect individual learners and diverse learning communities
V2 Promote participation in higher education and equality of opportunity for learners
V3 Use evidence-informed approaches and the outcomes from research, scholarship and continuing professional development
V4 Acknowledge the wider context in which higher education operates recognising the implications for professional practice
A lecturer is, in general, expected to meet the requirements to be a Fellow of the Higher Education Academy (Descriptor 2), which means:
Demonstrates a broad understanding of effective approaches to teaching and learning support as key contributions to high quality student learning. Individuals should be able to provide evidence of:
I. Successful engagement across all five Areas of Activity
II. Appropriate knowledge and understanding across all aspects of Core Knowledge
III. A commitment to all the Professional Values
IV. Successful engagement in appropriate teaching practices related to the Areas of Activity
V. Successful incorporation of subject and pedagogic research and/ or scholarship within the above activities, as part of an integrated approach to academic practice
VI. Successful engagement in continuing professional development in relation to teaching, learning, assessment and, where appropriate, related professional practices
EDIT: Note that the key point here is demonstrate. For each of the points above, there are clear ways to demonstrate that one understands them. For instance, "methods for evaluating the effectiveness of teaching" include asking feedback from students, performing comparative analysis from one year to another, engage in a reflective process, etc, so demonstrating this point is not just about saying "oh yes, I care that my teaching is effective".
