The notification system used by the Android and iOS operating systems is riddled with bugs, and even those who aren’t using it to report bugs are often forced to deal with annoying alerts, according to a study published Wednesday.
The researchers analyzed alerts sent to nearly 100 million people and found that nearly half of the users were either unaware of or unable to delete alerts they receive.
While Android users have access to a wide array of notification options, iOS users are limited to the standard three notification options—one for each app.
The study, which is based on Google’s own internal analysis of alerts sent by a subset of Android users, found that iOS users were the most likely to receive a notification when a bug or a security issue was detected.
That includes users who downloaded the latest version of an app and didn’t install any updates, and users who have used an app but haven’t installed updates yet.
It also found that those who downloaded an app, installed updates, but didn’t update their device to the latest release were more likely to be notified than those who did.
In the case of Apple’s iPhone, notifications are sent to users via a simple message that says “this app is outdated” and “this version of the app is not compatible with the latest versions of iOS.”
Users who download updates aren’t automatically notified, but rather have to do a bit of manual work to update their devices.
Apple’s iOS software is based largely on Android’s, so updates are typically delivered through the Apple App Store.
While the study noted that Apple users were also more likely than Android users to be able to delete notifications that were sent when a user didn’t have permission to do so, it said that in general, people on iOS devices are more aware of notifications.