What makes anyone confident in the accuracy of wearable tracking devices? I haven't seen it verified and I wouldn't assume it: Accuracy is expensive, generally speaking, and few consumers will pay for it or even question it - how often have you heard someone mention it?
Or, for example, have you wondered how accurate your simple bathroom scale is? I looked into it a little, wanting to collect accurate health data: IIRC +/- 0.1 kg (~0.2 lbs) is available in <$100 scales, but for real precision you need the $500 scales at your doctor's office. And how consistent is it? I tested mine, a decent one with good reviews, and getting it to report the same weight in immediately consecutive measurements was a challenge; I had to stand on it in just the right way.
Here are a couple articles that found the accuracy of activity trackers wanting. I've seen other articles in places like ZDnet that found the same problems, though based on less rigorous research.
I'm not sure what the value of a more accurate scale would be for a bathroom scale - your weight varies by far more than 100g just based on what you've eaten and how much water you've retained.
A guess: Two uncertain data points makes it even worse. If you can at least depend on the scale, the error is lower.
I tested our old Nintendo wii (or whatever it's called) balance board and so far it gives the same value every time I step on it. The value was also only 0.2 kg off from the doctors expensive scale.
The > at the end of your sporttechie link is making it 404, but here's the important part:
“What the plaintiffs’ attorneys call a “study” is biased, baseless, and nothing more than an attempt to extract a payout from Fitbit. It lacks scientific rigor and is the product of flawed methodology. It was paid for by plaintiffs’ lawyers who are suing Fitbit, and was conducted with a consumer-grade electrocardiogram – not a true clinical device, as implied by the plaintiffs’ lawyers. Furthermore, there is no evidence the device used in the purported “study” was tested for accuracy.”
Fitbit’s research team rigorously researched and developed the technology for three years prior to introducing it to market and continues to conduct extensive internal studies to test the features of our products. Fitbit Charge HR is the #1 selling fitness tracker on the market, and is embraced by millions of consumers around the globe.
Consumer Reports independently tested the heart rate accuracy of the Charge HR and Surge after the initial lawsuit was filed in January and gave both products an “excellent” rating. We stand behind our heart-rate monitoring technology and all our products, and continue to believe the plaintiffs’ allegations do not have any merit. We are vigorously defending against these claims, and will resist any attempts by the plaintiffs’ lawyers to leverage a settlement with misleading tactics and false claims of scientific evidence.
Good point (and sorry for the link, which I'm too late to fix). However, if we take Fitbit's statement at face value, we should infer that Fitbit is as biased and unreliable as the other side, so I wouldn't write off that research.
What makes anyone confident in the accuracy of wearable tracking devices? I haven't seen it verified and I wouldn't assume it: Accuracy is expensive, generally speaking, and few consumers will pay for it or even question it - how often have you heard someone mention it?
Or, for example, have you wondered how accurate your simple bathroom scale is? I looked into it a little, wanting to collect accurate health data: IIRC +/- 0.1 kg (~0.2 lbs) is available in <$100 scales, but for real precision you need the $500 scales at your doctor's office. And how consistent is it? I tested mine, a decent one with good reviews, and getting it to report the same weight in immediately consecutive measurements was a challenge; I had to stand on it in just the right way.
Here are a couple articles that found the accuracy of activity trackers wanting. I've seen other articles in places like ZDnet that found the same problems, though based on less rigorous research.
Accuracy of Smartphone Applications and Wearable Devices for Tracking Physical Activity Data in JAMA <https://jamanetwork.com/journals/jama/fullarticle/2108876>
Accuracy Of Fitbit Data Seriously Questioned By New Study <https://www.sporttechie.com/accuracy-of-fitbit-data-seriousl...
(Sorry if this disrupts your confidence in your data!)