It’s Not Nerd Parenting Without Graphs

Posted by Chad Orzel on August 10, 2010
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SteelyKid had her two-year checkup this morning, which means we got new weight and length measurements for her. It’s been a while since I did anything really dorky with her data, so here are a couple of graphs tracking her growth:

i-7936d46cf3e230c9ebd136e05f5b5202-2yrlength.png

i-cbc7fdb877333e397d677946297f17d7-2yrweight.png

(Yes, they’re in English units, not SI. Deal with it.)

Using the rule of thumb somebody mentioned a while back that a person’s final height is double their height at age 2, this projects her to be a bit over 5’9″, so that’s a prediction we’ll be able to test in another fifteen years or so. There’s some fairly large uncertainty in these, though, especially today’s points, as she’s now strong enough to be difficult to hold down for an accurate length measurement. By next year’s check-up, we should be able to get her height while standing, and make a game of it.

In the last two years, she has increased in length by almost 75%, and her weight has gone up by a factor of 3.6. Kind of amazing, really.

The weight graph in particular shows a couple of plateaus. The 15-20 month plateau is probably due to the series of wretched colds she had this winter, during which she wasn’t eating much (the doctor she saw in December was concerned enough to schedule some weight-check appointments, hence the larger than normal number of points in that interval). Both her height and weight are at the 75th percentile, according to the chart I got from the doctor today.

I’d do some curve fitting to these, but I no longer have SigmaPlot at home, and trying to get anything reasonable out of Excel is too painful. Maybe later.

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Comments

  1. #1 Art
    August 10, 2010

    If you want to win the prize for nerdy daddy have those graphs reduced and laminated into wallet-size and include them into the twenty section flip-down of baby pictures and proud-papa ‘look-at-my-darling-daughter’ pictures. Being able to document the exceptional progress of Steelykid in both picture and graph will set you apart. Being able to quote her progress in both percentage and standard deviations above normal from memory will seal the deal.

    Keep up the good work.

  2. #2 thm
    August 10, 2010

    One way to take this sort of nerdiness further–which I did in part to demonstrate that our now-three-year-old was, in fact, fine, in the first months of his life–is to get the data used to generate growth charts and use that to calculate and plot how the height/weight percentiles of your child vary with time.

  3. #3 Thony Christie
    August 10, 2010

    Yes, they’re in English units, not SI.

    A real nerd would know that they are not English but Imperial units ;)

  4. #4 Thomas Lennartsson
    August 10, 2010

    I also think it would be interesting to plot her weight over her length as a function of age. I’m sure we will see interesting things in such a figure.

  5. #5 Phillip IV
    August 11, 2010

    In the last two years, she has increased in length by almost 75%, and her weight has gone up by a factor of 3.6.

    If she keeps that up, by age 18 she should be 256’6” and weigh about 370 metric tons, so you could use a real sky bison for size comparison.