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).

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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 Forum: Apple Watch

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Top Rated Comments

csfossett Avatar
38 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
38 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
38 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
38 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
38 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
38 months ago
Apple: this watch is your health monitor!

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