Why Self-Track? The Possibility of Hard-to-Explain Change

My personal science introduced me to a research method I have never seen used in research articles or described in discussions of scientific method. It might be called wait and see. You measure something repeatedly, day after day, with the hope that at some point it will change dramatically and you will be able to determine why. In other words: 1. Measure something repeatedly, day after day. 2. When you notice an outlier, test possible explanations. In most science, random (= unplanned) variation is bad. In an experiment, for example, it makes the effects of the treatment harder to see. Here it is good.

Here are examples where wait and see paid off for me:

1. Acne and benzoyl peroxide. When I was a graduate student, I started counting the number of pimples on my face every morning. One day the count improved. It was two days after I started using benzoyl peroxide more regularly. Until then, I did not think benzoyl peroxide worked well — I started using it more regularly because I had run out of tetracycline (which turned out not to work).

2. Sleep and breakfast. I changed my breakfast from oatmeal to fruit because a student told me he had lost weight eating foods with high water content (such as fruit). I did not lose weight but my sleep suddenly got worse. I started waking up early every morning instead of half the time. From this I figured out that any breakfast, if eaten early, disturbed my sleep.

3. Sleep and standing (twice). I started to stand a lot to see if it would cause weight loss. It didn’t, but I started to sleep better. Later, I discovered by accident that standing on one leg to exhaustion made me sleep better.

4. Brain function and butter. For years I measured how fast I did arithmetic. One day I was a lot faster than usual. It turned out to be due to butter.

5. Brain function and dental amalgam. My brain function, measured by an arithmetic test, improved over several months. I eventually decided that removal of two mercury-containing fillings was the likely cause.

6. Blood sugar and walking. My fasting blood sugar used to be higher than I would like — in the 90s. (Optimal is low 80s.) Even worse, it seemed to be increasing. (Above 100 is “pre-diabetic.”) One day I discovered it was much lower than expected (in the 80s). The previous day I had walked for an hour, which was unusual. I determined it was indeed cause and effect. If I walked an hour per day, my fasting blood sugar was much better.

This method and examples emphasize the point that different scientific methods are good at different things and we need all of them (in contrast to evidence-based medicine advocates who say some types of evidence are “better” than other types — implying one-dimensional evaluation). One thing we want to do is test cause-effect ideas (X causes Y). This method doesn’t do that at all. Experiments do that well, surveys are better than nothing. Another thing we want to do is assess the generality of our cause-effect ideas. This method doesn’t do that at all. Surveys do that well (it is much easier to survey a wide range of people than do an experiment with a wide range of people), multi-person experiments are better than nothing. A third thing we want to do is come up with cause-effect ideas worth testing. Most experiments are a poor way to do this, surveys are better than nothing. This method is especially good for that.

The possibility of such discoveries is a good reason to self-track. Professional scientists almost never use this method. But you can.

8 Responses to “Why Self-Track? The Possibility of Hard-to-Explain Change”

  1. Jim Purdy Says:

    Getting taken seriously when I do any self-tracking is an uphill battle when I’m dealing with arrogant jerks in long white coats (a.k.a. MDs).

    They dismiss my experiences as anecdotal, and if I don’t slavishly follow their “doctor’s orders,” they call me noncompliant, nonadherent, crazy, and suicidal.

    At that point, I have a name for them.

    I call them my ex-doctors.

    An arrogant jerk is still an arrogant jerk, even if the jerk wears a long white coat.

  2. Lisa Wiland Says:

    I’m interested in self-tracking, but I haven’t figured out HOW to do it (without it being too cumbersome / time consuming / inconvenient). Is there something you’ve written (or someone else has written) that gives tips to a beginner? I imagine you’ve learned a lot over years of doing this about what makes it easy enough to stick to.

    When you suggest that one measure something daily, then wait and see … well, I’m trying to think about what sorts of things are likely to be worth measuring. I guess that depends on the individual, and what issues/problems they’d like to improve. Sleep and mood are clearly useful ones. Weight too…. But I’m curious – what do YOU measure daily? And – about how much time does your self-tracking take (not analyzing / making connections, just the stuff you record each day)?

  3. Seth Roberts Says:

    I measure daily: 1. weight. 2. fasting blood sugar. 3. sleep. 4. brain function. It takes about 7 minutes.

  4. Jim Purdy Says:

    Seth, Im sorry, but I’m still a skeptic about your butter-arithmetic hypothesis, and your assertion that consuming butter makes you feel better.

    In one of the Public Library of Science blogs, “Obesity Panacea,” a recent post called “Does thinking hard impact your heart?” made this statement:

    “The results of this study suggest that an experimental mental work condition consisting of a 45-min period of reading and writing a summary, as other types of mental work (such as arithmetic) utilized in the laboratory, can modulate cardiovascular responses in healthy young adults through a reduction in cardiac parasympathetic activity.”

    In other words, perhaps it is the mental work (arithmetic), not the butter, which makes you feel good. (But my long-ago calculus class at Duke in 1961-62 sure didn’t make me feel good. And the grade I got really made me feel bad.)


    Seth: I believe butter makes me faster at arithmetic. From your comment I am unable to figure out why you question this. I have not studied mood effects of butter.

  5. Nancy Lebovitz Says:

    I’ve heard about that sort of neutral accumulation of data in studying nature– there are projects that keep track of bird-watching results. I’ve heard of another project of that sort done by scientists– I’ll post if I remember any more details.

    The Longevity Project is probably another one.

    Seth: Many scientific projects collect data over long periods of time (years). In psychology this is called longitudinal research. In psychology at least, the people who do these studies don’t try to learn the cause of sudden changes (if any). In what I’ve seen, they ignore them.

  6. Nancy Lebovitz Says:

    I agree that data accumulation is a rare way to do science, and there should be more of it.

    Seth: Data accumulation is common. Outlier investigation is rare.

  7. Shawn Says:

    Thanks for this post. Ever consider posting some of the templates you use for self-tracking?

    Regarding one-legged standing, I’ve been doing it for a few days now and am getting restorative sleep that I have rarely had since childhood, where I was on my feet for a large chunk of the day playing. I wonder why I didn’t think of doing something so simple on my own; clearly it would have helped to have used a journal.

  8. Adam Says:

    Seth, you wrote: “I measure daily: 1. weight. 2. fasting blood sugar. 3. sleep. 4. brain function. It takes about 7 minutes.”

    1. is obvious.
    2. I’m interested in, but a Glucometer is expensive. Are you testing only once a day? When do you test?

    Seth: I test once/day at 8 am.

    3. I’ve heard you describe before. You record your subjective feeling of restedness on a scale from 0 to 100, including decimals (ie 97.5).
    4. You test with solving arithmetic in some program. Any chance you could share the details if not the program itself?

    Seth: I will soon announce a way that a small number of people can use the test I now use. I no longer use an arithmetic test.