Thinking About Bioinformatics

 I’ve been thinking about how to make my draft textbook on “information metrics” more accessible.  In particular, I’ve spent some time looking at a text that I admire as very accessible — Feynman’s Lectures on Physics — to see what I could learn.  I thought I’d post some of my conclusions here.

Feynman achieves a remarkable combination of intellectual engagement — plugging you into the fundamental ideas of a problem area — and accessibility. Conventional textbook treatment uses formalism and jargon to elevate the author and distance the reader from the material. It feels like you are being inducted into the holy mysteries… which puts most people to sleep. Instead of stimulating your own questioning of the material, it implies that such Difficult and Important Ideas will require long, hard hours of study to get even a glimmer. Feynman could easily come across as “too smart for a normal human to understand”, but unlike some writers, that’s not what he wants. Somehow he is able to prick that bubble effortlessly and give you the feeling of a wonderful tour guide who is going to show you his favorite marvels. No barriers of jargon or “obfuscation-sophistication” get in the way of understanding him. He simply refuses the conventional academic tone. He doesn’t believe in it!

There is much for me to learn from Feynman’s example.

• One key to Feynman’s accessibility is his ability to break a complex body of material into short, self-contained “lectures” (especially in the 3 volume Feynman Lectures in Physics). Each lecture feels like a little guided tour, with very little barrier to entry, rather than “yet another chapter in a hefty textbook”. He takes your hand and whisks you off on the tour. Each chapter is only 8 - 10 pages long, which would probably be about 6 - 8 of my laTex pages, given the generous margins reserved in Feynman for his figures.

• He keeps asking questions so basic that even a freshman would be embarrassed to ask them (for fear of being considered a simpleton). By asking fundamental questions, Feynman both reveals how interesting and useful they are, and liberates you (the reader) to ask such questions yourself.

• This plays an important role in making each chapter approachable and self-contained. Each chapter starts with a thought-provoking introduction that asks basic questions anyone can understand — even if they haven’t read the preceding chapters. Even though the rest of the chapter gradually gets more technical (and requires background from previous chapters), he continuously re-raises the fundamental questions. Thus, it becomes possible to read Feynman on several different levels. You could read it just for the fundamental questions, observations and theories he presents so intuitively. You could actually learn a lot about physics even if you made little effort to master the equations. Since his math is as clear (and presented as simply) as his text, it will give you another level of understanding. At any rate, a principle emerges: fundamental questions make the material more approachable and easier to understand (on multiple levels), both by exciting our interest and by giving us the “bigger picture” in which we can see how each detail fits. Technicalities become integrated rather than fragmented.

• Engaging the reader with fundamental questions can shift his/her relationship with the material from passive to active. Typical undergraduate coursework emphasizes “knowing the right answer”. Feynman shows you the importance of asking the right question, and implies that you too could do this, with a little common sense and imagination. Most readers won’t make that leap, but some will be inspired.
• His tone is conversational. He uses exclamation points and italics liberally, turning the textbook into a conversation with an enthusiast. He peppers each chapter with dialogs that highlight possible confusions and subtleties. For example in a chapter selected at random (8), we find the following dialogs over the course of a few pages:
  • “Now, you may say, ‘This is all some kind of trivia,’ and indeed it is. How can we describe such a one-dimensional motion…?”, which leads into a step by step description of a car’s motion.
  • “Perhaps you say, ‘That’s a terrible thing–I learned that in science we have to define everything precisely.’ We cannot define anything precisely! If we attempt to, we get… philosophers… one saying… ‘You don’t know what you are talking about!’ The second one says, ‘What do you mean by know? What do you mean by talking? What do you mean by you?,’ and so on.”
  • “Zeno produced a large number of paradoxes… ‘Listen,’ he says, ‘to the following argument: Achilles runs 10 times as fast as a tortoise…’”
  • “In order to get to the subtleties in a clearer fashion, we remind you of a joke… the cop comes up to her and says, ‘Lady, you were going 60 miles an hour!’ She says…” He follows out the implications of this dialog for 3 paragraphs.
  • The rest of the chapter follows this spirit of question and answer. He asks a question, tries out an answer, asks another question… The only difference is that this dialog is not quoted as a conversation between two named characters. Instead, this dialog is between Feynman and the reader. He always addresses the reader as “you”, as if he were writing a letter rather than a textbook. He always speaks as “we” (”Now we have to discuss the inverse problem… Let us say, ‘In the first second her speed was such and such…’ ” )

• Feynman must have made a conscious decision to favor concepts over technicalities, and to govern the latter with a strict rule of necessity and clarity. His use of math is lucid and compact; he never allows it to take over the text or obscure the fundamental questions. His equations illuminate, and with the minimum effort necessary. This seems only sensible for a freshman course!
• Unlike many theorists, Feynman highlights the difference between science and math, and unabashedly declares his purpose to be scientific. His fundamental questions are about the universe and how it works, not about equations and what we can prove about them. In his lectures math comes second, only when needed to clarify a physics problem. Many theorists don’t see it this way. They’re mathematicians first and foremost, devoted mainly to their mathematical model and techniques, and view the physics (especially its empirical side) as a bastardized approximation of the mathematical beauty that interests them. The machismo (and ego) of mathematical rigor often drives this tendency into places where it doesn’t really help the student. A physics class can easily become a watered-down math course; all you have to do is bring in your favorite mathematical methods, and before you know it… Feynman vigorously refuses this path.

This entry was posted on Friday, July 18th, 2008 at 6:55 pm and is filed under writing. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.