For better presentations, avoid most presentation advice

If you want to become a better presenter, you probably should avoid most advice about presentations.

Yes, here I am, an educator, apparently telling people to avoid sources of knowledge. The problem is that much presentation advice is not a source of knowledge; more like a source of sophistry that helps perpetuate some of the worst problems with presentations.

As an avid reader of books, articles, and blog posts about presentations, I identified a few pathologies from the mass of material available:

1. Presentationism. This is what I call the tendency of people who do presentation training or information design training to focus on the style and delivery of the presentation instead of the substantive material that the presentation is about. This is a form of professional deformation, but one that can become a serious obstacle to understanding the real value of presentation skills: usually that of changing the audience's mind, unless the presentation is being done for entertainment, legal, or other purposes.

2. Perfectionism. The idea that all presentations have to be done to the standard of excellence and that all presenters should put as much effort as needed into preparing, rehearsing, delivering, and clarifying every presentation. In reality there are many people who have to do presentations with minimal resources, for whom the time and effort required to create a better presentation represent a net loss of value.

3. Ideological purity. Instead of choosing the best tool for a given presentation, many authors are strict ideologues: the presentation should conform to their choice of tool and styles. This affects some famous authors in information design and presentation techniques, and has led to pointless arguments about which tool is better, tout court. Like arguing whether a hammer or a drill is a better tool, independently of the project, and equally pointless. This creates a subordinate problem:

4. Subject matter and audience independence. According to a plurality of authors, Einstein presenting to an audience of Princeton scientists and the Frito-Lay head of sales for northeast Kentucky reporting on the penetration of new chip varieties to a group of mid-level executives should prepare and deliver their presentations in about the same manner, with similar presentation support (typically, though not always, slides), and about the same effort. To be clear, these authors don't suggest that the substance of the presentation should be the same, but rather that the process of preparing and delivering these presentations and the style and design of the materials should be the same.

5. The "tricks and tips" distraction. Many authors offer only tricks and tips, which may be good or bad, but in general create a false sense of learning: the problem with most bad presentations is systemic, not something that a tip will solve. Similarly, a lot of authors use cherry-picked results from psychology to support their approach. As a general rule, unless you can read the original source and determine whether the result applies to your circumstances, it's better to ignore this.


So, what is someone who wants to become a better presenter to do? I've written about it (note the "most" in the title above, which is not "all" on purpose), and here are three further recommendations:

- James Humes's Speak like Churchill, Stand like Lincoln is a short, well thought-out book on public speaking.

- Edward Tufte's books, courses, and web site, despite a bit of ideological purity, are possibly the best source for people for whom getting complex messages across to their audience is important and worth the effort.

- Don Norman's critique of Tufte makes a good counterpoint piece for ET's works.

Above all, think critically about the advice being given; ask "does this make sense in my case?" Even the best advice has exceptions.

On hiatus

I'll be taking a break from blogging in order to finish a number of writing projects.

I'll probably tweet the occasional pithy thought and post any photos I find interesting. But long-form blogging is unlikely to continue in the previous form; when I return I'll probably be posting book notes or observations about coding in R.

How misleading "expected value" can be

The expression "expected value" can be highly misleading.

I was just writing some research results and used the expression "expected value" in relation to a discrete random walk of the form

$x[n+1] = \left\{ \begin{array}{ll}
   x[n] + 1 & \qquad \text{with prob. } 1/2 \\
  & \\
   x[n] -1 & \qquad \text{with prob. } 1/2
   \end{array}\right. $ .

This random walk is a martingale, so

$E\big[x[n+1]\big|x[n]\big] = x[n]$.

But from the above formula it's clear that it's never the case that $x[n+1] = x[n]$. Therefore, saying that $x[n+1]$'s expected value is $x[n]$ is misleading — in the sense that a large number of people may expect the event $x[n+1] = x[n]$ to occur rather frequently.

Mathematical language may share words with daily usage, but the meaning can be very different.

----

Added Nov 27: In the random walk above, for any odd $k$, $x[n+k] \neq x[n]$. On the other hand, here's an example of a martingale where $x[n+1] = x[n]$ happens with probability $p$, just for illustration:


$x[n+1] = \left\{ \begin{array}{ll}
   x[n] + 1 & \qquad \text{with prob. } (1-p)/2 \\

  & \\
   x[n]  & \qquad \text{with prob. } p \\

  & \\
   x[n] -1 & \qquad \text{with prob. } (1-p)/2
   \end{array}\right. $ .

(Someone asked if it was possible to have such a martingale, which makes me fear for the future of the world. Also, I'm clearly going for popular appeal in this blog...)

Why I'm somewhat apprehensive about Apple's reshuffle

Though I'm not as pessimistic about the Apple executive shuffle as the markets and Joy Of Tech, I'm apprehensive regarding the future of Apple's products.

Jony Ive is a great industrial designer, but Human-Computer Interaction is not Industrial Design. And some of the design decisions in recent hardware (meaning Ive's decisions) seem to ignore realities on the field. Take the latest iMac.

The new iMac doesn't have an optical drive; some pundits (and, I think, Phil Schiller on the Apple event) say that's a normal evolution. After all there aren't floppy disks on computers any longer and Apple was the first to drop them. And look how pretty the tapered edges of the iMac are.

Floppy disks existed as part of a computer-only ecosystem. CDs, DVDs, and BluRay Discs are part of a much larger ecosystem, which includes dedicated players and big screen TVs, production and distribution chains for content, and a back catalog and personal inventory for which downloads are not a complete alternative. (Some movies and music are not available as downloads and people already have large collections of DVDs and BluRay Discs.)

Using floppy disks as an example of change, implying that it is repeated with optical drives, shows a complete disregard of the larger ecosystem and willful ignorance of the difference between the earlier situation and the current situation.

For a laptop, the absence of an optical drive may be an acceptable trade-off for lower weight; for a desktop, particularly one that is a "home" desktop with a HD screen, the lack of a BluRay/DVD/CD drive is a questionable decision.

But look how pretty the tapered edges are, here in the uncluttered Apple Store retail shelves — oops, those computers will be in cluttered real world environments, where the necessary external drive (what, no BluRay drive yet, Apple?) will add even more clutter.

But, on the empty tables and antiseptic environments of "minimalist" designers' imagined world, that tapered edge is really important.

In the rest of the world, there are scores of people who like watching really old movies (available on DVD, not as downloads or streaming — except illegally), new movies in 1080p discs with lots of special features (i.e. BluRay discs that they can buy cheaply in big box stores), or their own movies (which they already own, and could rip — in violation of the DMCA — for future perusal, as long as they want piles of external hard drives); or maybe they want to rip some music that isn't available in download format, say CDs they bought in Europe that aren't available in the US yet.

So, using a decision that is not isomorphic at all (dropping the floppy disk) as a justification, Apple ignores a big chunk of the value proposition (consumption of media that is not available via digital download) on behalf of elegance. And, perhaps some extra iTunes sales — probably too small to make a difference on the margin.

What will this type of philosophy do to software? As Donald Norman wrote in this piece, there's nothing particularly good about fetishizing simplicity. Even now, many power users of Apple products spend a lot of time developing work-arounds for Apple's unnecessary rigid limitations.

Steve Jobs's second stint at Apple had the advantage of his having failed twice before (his first stint at Apple and NeXT), which tempered him and made him aware of the power of ecosystems (not just network effects). This is a powerful learning experience for an executive. Jony Ive hasn't failed in this manner.

Yet.

Can we stop talking about "manufacturing jobs"?

A lot of people worry about "manufacturing jobs," but the metric is seriously flawed.

Politicians and some financial analysts decry the decline of manufacturing jobs. There has been some decline, but the way these jobs are measured is inherently flawed, as it fails to take into account the change in managerial attitudes towards vertical integration.

Easy to see why with an example:

Ginormous Corp. makes widgets. In the 60s to mid-80s, as it went from being Bob's Homemade Widgets to Ginormous Corp., it added new facilities which had janitorial, accounting, cafeteria, legal, and other support services. All personnel in these support services counted as "manufacturing jobs."

In the mid-80s, Ginormous Corp. figured out (with a little help from Pain & Co and McQuincy & Co consultancies) that these support services were (a) not strategic and (b) internal monopolies. Part (a) meant that they could be outsourced and part (b) strongly suggested they should be outsourced. Let's say that Ginormous Corp. spun out these support services into wholly-owned subsidiaries, with no significant change in overall personnel.

So, all the personnel in janitorial, accounting, cafeteria, legal, and even some of the technical business support went from being in "manufacturing jobs" to being in "service jobs" without any change to what actually is produced and any actual job.

A metric that can change dramatically while the underlying system and processes don't change much is not a good foundation for decision-making. "Manufacturing jobs" is one such metric, as it depends on organizational decisions at least as much as on actual structural changes.

Metrics: useful only when well-understood.

Note: There are many reasons why focusing on manufacturing jobs over service jobs is a bad idea: Old Paul Krugman explains the most relevant, differential productivity increases, here.

Math in business courses: derivating + grokking

I used to start my Product Management class with a couple of business math problems like the following: let's say we use a given market research technique to measure the value of a product; call the product $i$ and the value $v(i)$. We know -- by choice of the technique -- that the probability that the customer will buy $i$ is given by

$\Pr(i) = \frac{\exp(v(i))}{1 + \exp(v(i))}$.

My question: is this an increasing or a decreasing function of the $v(i)$?

Typically this exercise divided students in three groups:

First, students who were afraid of math, were looking for easy credits, or otherwise unprepared for the work in the class. These math problems made sure students knew what they were getting into.

Second, students who could do the math, either by plug-and-chug (take derivative, check the sign) or by noticing that the formula may be written as

$\Pr(i) = \frac{1}{1 + \exp(-v(i))}$

and working the increasing/decreasing chain rule.

Third, students who had a quasi-intuitive understanding ("grok" in Heinlein's word) that probability of purchase must be an increasing function of value, otherwise these words are being misused.

Ideally we should be training business students to mix the skills of the last two groups: a fluency in basic mathematical thinking and grokking business implications.

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Administrative note: Since I keep writing 4000+ word drafts for "important" posts that never see the light of blog (may see the light of Kindle single), I've decided to start posting these bite-sized thoughts.

Thinking - What a novel idea

Or: it may look like brawn won the day, but it was really brains.

Yesterday I took some time off in the afternoon to watch the Blue Angels practice and the America's Cup multihull quarterfinals. Parking in the Marina/Crissy Field area was a mess and I ended up in one of the back roads in the Presidio. As I drove up, I saw a spot -- the last spot -- but, alas, there was a car in front of me. It drove into the spot, partly, then backed up and left.

I drove up to the spot and saw a block of cement with twisted metal bits in it, about three feet from the back end. I got out, grabbed the block, assessed its weight at about 100Kg, farmer-walked it to the berm, and got a parking spot.

Ok, so moving 100Kg or so doesn't make me the Hulk. What is my point, exactly?

There were at least two men in the car that gave up the space. They could have moved that block with ease. Instead they went in search of parking further into the Presidio; probably futile, if traffic was any indication. Why didn't they do what I did? Why didn't anyone before me (the parking areas well above the one I ended up in were already full as well)?

They didn't think of it.

Actually thinking is a precondition to problem-solving. Many problems I see are not the result of bad thinking but rather of the lack of thinking.