The Importance of Context

eagereyes 2017-07-18

I use a Misfit activity tracker to count my steps. The Misfit app does a decent job of showing me step counts per day and every month, misfit also sends me a summary of the previous month’s activity. Unfortunately, the numbers in that summary are presented without any context, making that summary almost entirely useless.

Misfit’s Missteps

The data in the screenshot is from April. I took close to 490,000 steps, earned some number of points, burned over 100,000 calories, traveled 281 somethings, and slept 215 hours.

Okay. Now what? Is that a lot? How am I supposed to know? What does it even mean to sleep 215 hours in a month? That’s not a meaningful way of stating that number. And notice that all the fields with numbers have the unit in the name, except for distance. I’m assuming it’s 281 miles, but why not state that?

Meaningful Units

The steps are quite easy to turn into something meaningful: April has 30 days, so that’s about 16,230 steps per day. That’s not bad if you set a goal of 10,000 per day (though we’ll get to a caveat in a bit). I do track my steps when I run (unless I leave the tracker at home, which happens), so this isn’t just me walking around. But it’s still hard to put into context.

Points are largely meaningless and I never pay attention to them. Misfit’s system gives you more or fewer points per step depending on what it thinks your effort level is. That’s a good idea, but it’s hard for me to do much with the total number of points, even the daily number I see in the app.

Calories! Now we’re talking! Close to 103,000 over 30 days is over 3,400 per day on average. That’s quite a bit. Of course, it’s based purely on the accelerometer in the step counter, not heart rate or anything like that. So it’s bound to be a pretty rough estimate.

The same is true for distance: 281 (miles, I assume). I ran about 180mi in April, which happens to be the most I’ve ever run in a month. It’s possible that I’ve walked another 100mi, but it’s still based on widely inaccurate step counter data.

Sleep is where it gets problematic. 215 hours of sleep total means about 7 hours and 10 minutes per night. That doesn’t seem unreasonable, but I don’t know if I tracked every single night. Using an average here would not only be much more meaningful, it would also allow them to account for nights where they don’t have data (and the fact that different months have different numbers of days/nights) and give me a number I can trust (if I missed just one night, the average increases by 15 minutes, which is quite a difference).

Context: An Outlier

Now both Misfit and I know that there’s an outlier in my data. It’s even on this summary: April 30. I ran the Big Sur Marathon that day and took over 50,000 steps. The summary says that this was my best day, but it doesn’t exactly tell me by how much: it’s almost 20,000 steps more than any other day during that month (and those days are long runs, so they’re also outliers). That seems relevant to point out, not just as a single “best day” – which could just be a fairly regular day.

The entire month is at least remarkable for the fact that it’s the most distance I’ve ever run in a calendar month, which also makes it the most steps I’ve ever taken in a month. Pointing that out would put the data into larger context than just that one month.

More Context

There is a lot more potential to add context here. I still don’t know if any of those numbers are any good (at least Misfit hasn’t told me). How am I doing compared to people of my gender and age range? How has my own data changed over time? Was this better or worse than the month before? How does this compare to the same month a year ago? How about several years back (assuming I’ve had the tracker long enough)?

Going further, what about setting a goal and showing me progress? Misfit doesn’t let me do that, but Strava does a decent job at this for both weekly and yearly goals.

Even this could be improved (and I’ll have more to say about data display in fitness tracking more generally in another posting), but it’s a good start.

All of this is context, and it’s important if I’m supposed to get any value out of these numbers. Just throwing digits at me without an idea what would be good or bad (should I aim to sleep 15 hours more this month?) doesn’t help me. Numbers need to be stated in units I can understand (like hours of sleep per night), and I need some context to understand what’s good or bad – and ideally, how I’m doing relative to others or just myself.

If you expect me to understand numbers, you need to give me context.