Thanks for the thoughtful insights Hans. I really liked how you emphasized a very subtle fact — that any conversation you craft, you craft it for the ear, not the eye. What might seem OK in paper (written language), often is not ideal when reading it out loud (spoken language). There are so many subtleties in language that no wonder linguists are having a blast in this day and age of conversational design.
Just one point I wanted to make is that some of these rules should be taken with a grain of salt based on your context and the type of bot you’re building.
For example, “always speak one-on-one” makes sense in most situations, but there can be some others where you might actually want to create a separation between you and the user. Imagine for a second the user is requesting something that your business doesn’t allow them to do (e.g. extend a payment date). In that case, you want to acknowledge the request, but probably wouldn’t want to be the one telling the user “Sorry, I cannot let you move the date that far out.”. In cases like that, you might be better off referring to “the system” or some other 3rd party element being the culprit behind the unexpected result. A similar situation arises when there’s a benefit the company is providing, and therefore you want to extend the credit beyond the scope of the bot, as in “We’re so excited to welcome you to the family!”
Another example is “keep it short”. Again, for most situations I would agree with keeping things short, sweet and to the point. But again, based on the context of the conversation, there are cases where additional information, alternative solutions or step-by-step instructions might be the best way to help the user move forward towards their goal. I often see this in situations where we ask users to provide a piece of information they may not be very familiar with (hence the need for an explanation on why we need it or where to find it), they are giving us an unexpected/invalid response (here we can give hints about the data we’re looking for, tell them about the format, or present alternative ways of entering the information)