I have a colleague who gives great talks. There are three reasons they are great. (1) The science is great. (2) He speaks engagingly and explains his (complex)

I have a colleague who gives great talks. There are three reasons they are great. (1) The science is great. (2) He speaks engagingly and explains his (complex) material very well.(3) He always includes a citation and some very specific remarks on the single paper that I can read, to learn more. This third thing is the most important to the growth of the academic field, because solitary study is usually required to make progress, and nobody has time to read dozens of papers in a field that is not quite their own.