That’s just not true, as others have indicated. Although BlueTooth can be detected at greater distances and though walls, the strength of such signals can easily be determined and programmed to reject all those that don’t exceed a specific threshold or that are not being received continuously over a prescribed period. I would hope that the apps will be carefully designed to reduce the frequency of such false detections.
Thanks, I got it! Great feature. :-)
I agree that could reduce false positives, but that was not clear to me from the technical documents I read.
Interesting. So yes, Bluetooth can detect if another device is nearby, but that is not the same thing as accurately measuring distance. For example, I would expect you would need to get closer if someone was between you and your Mac. The Mac unlocks when some signal strength threshold is passed, but that does not necessarily equate to a specific distance.
That is correct, however that does not necessarily exclude signals coming from outside a room. For example, in apartment buildings, Bluetooth signals from a neighbor can easily be as strong as those from yourself. So basically, what I wrote is true. You might be able to reject many false signals, but certainly not all. And the more signals you reject, the higher the chance you also reject correct signals. So whatever algorithm they come up with, it will be a compromise.
The big question is, how dependable will this app be? Will people trust it? You need to be significantly altruistic to use such an app, because it will not protect you from Corona, it is meant to protect others. Nothing wrong with that of course, but if the app makes people go into quarantine wrongly, trust will fly out the window and people will stop using it. So they better get it right first time.
Off-topic.
On the same line as your name, just to the left of the relative time (for example, it says 22h as I type this), there is an indication that your post responded to @ddmiller’s post. When I clicked on the arrow indicating a reply, I was shown the post to which you were replying, with the option of navigating to that post.
Until I learned that trick, I was occasionally frustrated when someone did not quote what prompted his or her reply.
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That’s not my understanding. I believe it’s designed to provide contact tracing statistics to medical analysts to better understand how it’s spread. It may also help to protect others in the process, just not what it’s been advertised.
Perhaps it is different from country to country. Yes, contact tracing statistics is one goal, but where I live the main goal would be to prevent the virus from spreading by reducing the R0 (factor of number of other people someone infects) to below 1. This can be achieved by (self) quarantining anyone that has (potentially) been in contact with someone that has, at a later time, been diagnosed with Corona. By (self) quarantining after the app warns you, you protect others.
Apple and Google announced today via a background briefing that they are released a beta version of the API for COVID-19 exposure tracking. It’s being released only to a subset of developers associated with public-health authorities; not a general release.
The two companies also said today that they will allows public-health authorities to set parameters around the exposure levels they consider important to inform others about. In earlier drafts of the standards—as discussed in this forum—there were questions and not a lot of answers about how Bluetooth positioning data could be used to ensure only close-contact matches would be made.
In this revision in the beta process, the companies say that developers can incorporate this data from public-health authorities into the apps so that the apps can provide information appropriate to the distances and time exposed. All of the exposure information will remain on each individual device, so no central authority will be able to access it. However, the apps can use the API’s analysis of proximity and duration to offer up custom details.
While the companies didn’t offer guidance to what that would look like, my understanding is that it could be the difference between, “On 14 April, you were within 50 feet for more than 30 minutes of someone who has tested positive for the novel coronavirus on 18 April. Contact xyz to discuss testing” and “On 14 April, you spend 15 minutes within five feet of someone who has tested positive on 18 April. Please immediately quarantine yourself for 14 days from all contact with other people, and contact XYZ for information about obtaining in-home or in-car testing.”
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Reuters is reporting that Apple and Google’s contact-tracing API will ban developers from accessing GPS data.
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