Researchers Struggle to Use Apple Watch in Studies Due to Sudden Algorithm Changes

Researchers are rethinking plans to use the Apple Watch in studies after finding inconsistencies in the data gathered by the device (via The Verge).

apple watch series 6 product red back
Inconsistencies in the Apple Watch's heart rate variability data are reportedly caused by Apple tweaking the device's algorithms, meaning that data from the same time period can change without warning. Associate professor of biostatistics at the Harvard T.H. Chan School of Public Health and developer of the Beiwe data platform, J.P. Onnela, told The Verge:

These algorithms are what we would call black boxes — they're not transparent. So it's impossible to know what's in them.

Research fellows at Brigham and Women's Hospital exported the heart rate data from Apple Watches for the same period of time, but several months apart. The data should have been identical, but since it is filtered through an algorithm prior to export it was drastically different.

Apple changes its algorithms regularly and without warning, so exporting the same data at different times may use different algorithms. Beyond heart rate variability, researchers looking into sleep tracking have experienced similar problems with changes to algorithms.

This mostly precludes commercial devices from being used by researchers, resulting in the need for devices specifically designed to collect data for scientific studies. While this is adequate for some studies, it heavily constrains research into the medical value of commercially available products for users. Some researchers say that Apple should publicize the changes it makes to algorithms or make the Apple Watch's raw data available.

Related Roundups: Apple Watch 10, Apple Watch SE
Related Forum: Apple Watch

Popular Stories

iPhone SE 4 Thumb 1

iPhone SE 4 With Apple's Own 5G Modem 'Confirmed' to Launch in March

Tuesday November 19, 2024 12:12 pm PST by
Barclays analyst Tom O'Malley and his colleagues recently traveled to Asia to meet with various electronics manufacturers and suppliers. In a research note this week, outlining key takeaways from the trip, the analysts said they have "confirmed" that a fourth-generation iPhone SE with an Apple-designed 5G modem is slated to launch towards the end of the first quarter next year. In line with previo...
airtag purple

AirTag 2 Rumored to Launch Next Year With These New Features

Sunday November 17, 2024 5:18 am PST by
Apple released the AirTag in April 2021, so it is now three over and a half years old. While the AirTag has not received any hardware updates since then, a new version of the item tracking accessory is rumored to be in development. Below, we recap rumors about a second-generation AirTag. Timing Apple is aiming to release a new AirTag in mid-2025, according to Bloomberg's Mark Gurman....
Magic Mouse Next to Keyboard

No, Apple CEO Tim Cook Didn't Say He Prefers Logitech's MX Master 3 Over the Magic Mouse

Sunday November 17, 2024 3:03 pm PST by
While the Logitech MX Master 3 is a terrific mouse for the Mac, reports claiming that Apple CEO Tim Cook prefers that mouse over the Magic Mouse are false. The Wall Street Journal last month published an interview with Cook, in which he said he uses every Apple product every day. Soon after, The Verge's Wes Davis attempted to replicate using every Apple product in a single day. During that...
Generic iOS 18 Feature Real Mock

Apple Releases iOS 18.1.1 and iPadOS 18.1.1 With Security Fixes

Tuesday November 19, 2024 10:10 am PST by
Apple today released iOS 18.1.1 and iPadOS 18.1.1, minor updates to the iOS 18 and iPadOS 18 operating systems that debuted earlier in September. iOS 18.1.1 and iPadOS 18.1.1 come three weeks after the launch of iOS 18.1. The new software can be downloaded on eligible iPhones and iPads over-the-air by going to Settings > General > Software Update. Apple has also released iOS 17.7.2 for...
at t turbo indicator iphone 16 pro max v0 8hrh7w5f3w1e1

AT&T Turbo Indicator Showing Up in iPhone Status Bar for Subscribers

Wednesday November 20, 2024 3:42 am PST by
AT&T has begun displaying "Turbo" in the iPhone carrier label for customers subscribed to its premium network prioritization service, according to reports on Reddit. The new indicator seems to have started appearing after users updated to iOS 18.1.1, but that could be just coincidence. Image credit: Reddit user No_Highlight7476 The Turbo feature provides enhanced network performance through ...
iPhone 17 Slim Feature Single Camera 1 Redux

'iPhone 17 Air' Rumored to Surpass iPhone 6 as Thinnest iPhone Ever

Monday November 18, 2024 1:07 pm PST by
In a research note with Hong Kong-based investment bank Haitong today, obtained by MacRumors, Apple analyst Jeff Pu said he agrees with a recent rumor claiming that the so-called "iPhone 17 Air" will be around 6mm thick. "We agreed with the recent chatter of an 6mm thickness ultra-slim design of the iPhone 17 Slim model," he wrote. If that measurement proves to be accurate, there would be ...
bug security vulnerability issue fix larry

Make Sure to Update: iOS 18.1.1 and macOS Sequoia 15.1.1 Fix Actively Exploited Vulnerabilities

Tuesday November 19, 2024 10:52 am PST by
The iOS 18.1.1, iPadOS 18.1.1, and macOS Sequoia 15.1.1 updates that Apple released today address JavaScriptCore and WebKit vulnerabilities that Apple says have been actively exploited on some devices. With the JavaScriptCore vulnerability, processing maliciously crafted web content could lead to arbitrary code execution. The WebKit vulnerability had the same issue with maliciously crafted...

Top Rated Comments

csfossett Avatar
43 months ago
I have to admit I find this incredibly disconcerting. I get that companies like Apple are commercially driven, and algorithms tend to be in service to that, but they're also touting the Apple Watch as a major healthcare related device. Shouldn't medical/biological diagnoses and research be driven purely by data and information, and not by what amounts to programming developed to interpret data in advance of receiving it?
Score: 45 Votes (Like | Disagree)
hailey bee Avatar
43 months ago
It's the same principle as with raw format in photos – pro users need raw data.
Score: 32 Votes (Like | Disagree)
rjohnstone Avatar
43 months ago

Everyone here is a medical expert apparently
You don't have to be a medical expert to understand data analysis.
If the baseline data is changed via an algorithm update, you need to know how that algorithm was changed to account the data discrepancy.
Without the info, the data becomes useless.
Score: 19 Votes (Like | Disagree)
Malus120 Avatar
43 months ago
This is so incredibly disappointing, and yet also so undeniably Apple.

It's both funny and sad that one of the few aspects of Steve Jobs Apple that Tim Cook has chosen not to change, the company's intense secrecy, continues to be its downfall in so many current and potential markets.

Apple is fortunate to be the only real player in the wearables market at the moment. Despite the complaints, I would imagine most researchers will continue to work with Apple for the time being as they're the only game in town. That said, just as in the pro and corporate markets, Apple will eventually struggle to retain research clients in the long run if it continues to cling to its asinine refusal to provide even a basic level of transparency.

If Apple wants to expand outside of the consumer market in a serious way it needs to understand that secrecy is not the asset it is there but a serious liability that many folks just aren't going to be willing or able to deal with.
Score: 18 Votes (Like | Disagree)
rjohnstone Avatar
43 months ago

Welcome to working with data. Getting and pre-processing data to improve quality uses upward of 70% of the project time. Data is constantly changing due to legal or technical issues or to make it better for users other than you. Any study based on data needs to be able to handle these changes.
In order for a study to account for the changes, it needs to know what was changed. It would need the raw data or the algorithms to compare, so they can account for those changes.
Since Apple doesn't provide that information, the data collected is largely useless.
Score: 18 Votes (Like | Disagree)
Mrjetsondc Avatar
43 months ago
Apple: this watch is your health monitor!

also Apple: lol psych thanks for the 400 bucks
Score: 17 Votes (Like | Disagree)