Saturday, September 19, 2009

Small screen? How numerologist of you!

A friend asked me how I could watch movies on my 15" laptop screen. Why don't I connect it to my [old, CRT] 27" TV? My answer: Because the movie on the 15" laptop is much larger than on the 27" TV!

"Surely you jest. It can't be," explodes the interlocutor.

Yes, it is. The laptop sits about 50cm from me, the TV about 3.5m. So the laptop covers approximately the same fraction of my visual field as a TV seven times as large, or about 105". Since I watch both from the same slouchy bad posture on my overstuffed couch, the laptop is better. (Yes, it is linear to a first approximation; it's a simple homothetic projection with my eyes as the center.)

Talking about numbers without understanding their meaning is one of the afflictions of the modern-day citizen/consumer/audience/manager. Unthinking reactions to magnitudes (27 vs 15) without context (that the TV is much farther from my eyes than the computer screen) are common and the source of much dismay [when they affect me] or amusement [when they don't].

It's like a new form of numerology, where people use numbers as magic wands -- understanding of the underlying reality considered unnecessary. I have used the BMI as my bĂȘte noire and preferred example to motivate students about the follies of neonumerology, but I think that from now on I'll use this even simpler example first.

Numbers mean things. The things are what matters.

Monday, September 7, 2009

Inferences can be deceiving

Watching TV can make you act smarter. All it takes is thinking as you watch. For instance:

A car insurance company boasts that "customers who switched to [the insurance company] have saved an average of $ManyBucks." I'm sure that's true, and I'm sure many people make the wrong inference.

The wrong inference to make is that [the insurance company] has lower premiums than its competitors. Significantly so, given the average savings of $ManyBucks.

The right inference is: well, duh! Switching insurance companies is effortful; only people who save a significant amount are likely to switch. Thought experiment: would you switch insurance companies for $1/yr? What about $10/yr? What about $100/yr? What about $1000?

Failing to see that the advertised savings come from a sample that self-selects on those same savings, some people infer --- incorrectly --- that [the insurance company] must be cheaper. (This is an example of what statisticians call sampling on the dependent variable.)

This works to the advertiser's advantage mostly when people are buying new insurance rather than switching. After all, the switchers will know whether it makes sense to switch, but the new buyers may just use their perceptions to base their decisions.

As I said in the title, inferences can be deceiving.

Tuesday, September 1, 2009

Managing My Digital Life - Introduction to the series

I liked the (now defunct) Managing Your Digital Life podcast with Scott Bourne and Andy Ihnatko. So much of our lives has moved to the digital domain that how we manage that domain has risen in importance. Therefore, I decided to create a blog series in which I explore my own experiences with managing my digital life. In particular how different the digital world is from the sometimes called "real world" or "physical world" as if digital work and entertainment were unreal or its physical expression unimportant.

(Saying that I'll create a blog series strains credibility given how sparse postings have became in this, my fifth personal blog. My use of Twitter for micro-blogging, planned use of Posterous for mini-blogging, and the need to earn a living has made long posts unlikely.)

For example, here are some information products I created or used in the last few weeks:
  1. Shopping list for a grocery run, divided by retailer. Created with a fountain pen on a Moleskine.

  2. Data from exercise, entered into Apple Numbers. The late great Peter Drucker used to say that if you don't measure it you can't manage it. So, in order to manage exercise, I keep tabs on exactly how much I'm stuck on sticking points at the gym.

  3. Some tweets, created either on the website or on Twitteriffic for iPod Touch.

  4. This post, edited on TextWrangler.

  5. Large number of emails, processed in Inbox Zero fashion, mostly by deleting them.

  6. Large number of RSS feeds, forum postings, print media gone online, and web pages skimmed. Some read. A few copied and archived for future reference

  7. Commissioned work, in TextWrangler.

  8. My own papers, in LaTeX format.

  9. Academic papers in PDF. No, not "PDF format." The F in PDF is for Format.

  10. Data set for an academic paper, analyzed on my computer using Stata. I could have done the analysis in R, but since I have started this particular project on Stata, there was no reason not to conclude it there.

  11. Data set for another academic paper, processed on my computer using a program I wrote in R. (The difference between data processing and data analysis: when I'm analyzing, I spend most time thinking and then issue a command to test an hypothesis. When I'm processing data, I write the program, then leave it alone to run on the data.)

  12. Several nonfiction, non-work books on dead tree that I've been rereading at the end of the day.

  13. A Kindle book, read on the iPod Touch Kindle app. (My first Kindle book, purchased as a test.)

  14. Some reference math, economics, statistics, and technical business books.

  15. Several photos taken with my old trusty Canon 5MP camera.

  16. Several Keynote presentation masters, which I keep up to date even when I'm not using them. I updated my Marketing Analytics and Decision-Making and Consumer Behavior masters.

  17. Several InDesign handout masters, on the same topics and for the same reason as the presentation masters.

  18. Many MP3s and AACs of what is called in the retail channels "classical music."

  19. A few podcasts, heard while doing household chores, walking, BARTing, or waiting.

  20. A few chapters of an Audible audiobook. When out for a walk or on a grocery run.

  21. Some CDs of what is called in the retail channels "classical music."

  22. Several DVDs, mostly courtesy of Netflix and a couple from my private collection.

  23. The Snow Leopard update for my laptop.

Thinking about this [very incomplete] list, three dimensions come to mind:

First, work versus entertainment: At the most basic level, I can get by without the entertainment part (unhappily), but the work is how I fund my lavish lifestyle. Some of the work material is confidential and might have costly implications for me if its security was compromised.

A second dimension is what is necessarily in hard-drive or disc files (like data that I get to process or analyze) versus data that is conveniently placed in hard-drive or disc files. I used "hard drive" instead of "digital" because a printed book is a digital product, just not an electronic one. This second difference highlights the trade-off one makes between convenience on one side and privacy and longevity (think music CDs vs JAZ drives) on the other.

A third dimension is connectivity requirements. Living in the San Francisco Bay Area, I don't need a MiFi or even an iPhone to get connected easily, but for other areas always-on internet may be a very important consideration. Or to plan ahead for outages: for example, having off-line reading is important for those of us who travel a lot. Enter Instapaper and Evernote.

Identifying the dimensions of a decision problem is just a first step towards solution. This first post has but scratched the surface of what is involved in managing a digital life. I intend to elaborate on these dimensions (and others that may appear) and on other aspects of managing a digital life in this blog series, tagged MMDL.

My marketing training shows through, though: these are not dimensions of the technologies used for living a digital life -- they are the dimensions (some of the dimensions, at least) of the lifestyle. (Maybe I can take this series at some point and use if for teaching or exec-ed...)