Nowaday I often see a colloquial or even flippant writing style in UI messages. For instance MS Excel 2016 writes "We finished $task", "Spelling finished. Let's go ahead!" (Translated from German "Jetzt kann's weitergehen"), Youtube on iOS announces an update with "garbage brought away, ..., time for a nap.", GIMP "Eeek! $Error" etc. The messages might be meant friendly, but at least the Youtube message is literally telling nothing and I am a bit wondering. They remind me of Microsoft Clippy. Are these messages the results of serious user research or just a marketing attempt to appear modern and friendly?
Are these messages the results of serious user research or just a marketing attempt to appear modern and friendly?
Good question to ask. You cite a breadth of examples and it's anyone's guess why they do what they do. Informal style is definitely appropriate sometimes, depending on the context and the audience.
There are some rules of thumb published out there, this post for example references a voice and tone resource which is worth looking at. On another website, someone broached the topic of whether humor is ever appropriate in error messages and in that thread I share links to NNG's voice and tone guides.
So this doesn't answer your question directly, but maybe provides you with some material to make an educated guess why they did (or at least know what they can do better and why.)
Most platforms will have some user research behind the language in their UI and how it affects conversions, it’s not something that will be taken lightly and without a content strategy in place.
The reasons this is occurring is it makes platforms and products seem less robotic, cold and automated. The aim is to make them friendly, warm and human. This will have an effect on whether a user is more likely to trust them more if the language appears more human and allows the user to connect more with the platform or product rather than feeling like it’s just another big product and feel distant.
This is becoming a whole job role in itself. This has given birth to a fairly new role: the UX Writer. A UX Writer’s job is to make the user experience easier and helping a user achieve goals through the use of language. This is a fairly newish thing but it’s rising fast.