This is typically the user sliding their finger off one key and onto another e.g. the two images where they show the "p" being pressed but an "o" being typed. People just don't notice they slide e.g. touch started on p and they slid finger over to o before lifting.
It might help if you take a slo-mo video from a second phone showing the users finger movements on the screen. Unfortunately the touch point is a lot finer than the finger pad, so it still wouldn't be clear.
On Android there is a dev feature to show touch points which helps debug people's mistakes (and has the advantage of showing the actual touch points sent by the hardware on video of screen capture). On iOS maybe similar feature in some custom keyboard Apps (or configuration choices?).
This is typically the user sliding their finger off one key and onto another e.g. the two images where they show the "p" being pressed but an "o" being typed. People just don't notice they slide e.g. touch started on p and they slid finger over to o before lifting.
I've described this better in another comment which has a better video of the problem in the related article: https://news.ycombinator.com/item?id=46242496
It might help if you take a slo-mo video from a second phone showing the users finger movements on the screen. Unfortunately the touch point is a lot finer than the finger pad, so it still wouldn't be clear.
On Android there is a dev feature to show touch points which helps debug people's mistakes (and has the advantage of showing the actual touch points sent by the hardware on video of screen capture). On iOS maybe similar feature in some custom keyboard Apps (or configuration choices?).
https://archive.is/g2mWU
does it though? my experience is that it still hot garbage.
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