A test plan is a tool you use while planning a period of testing. It basically describes what will be tested, who will do it, where they will do it, and how they plan on doing just that. In some coorperations, where law and contracts are really important, test plans are usually the size of a small child, and nobody ever reads it. Apart from lawyers. That's because test plans aren't always made for you - they can also be made for your team or for different stakeholders.
Chatbots already exist, and have done so for decades. But the classical bots from "ye olden days" have their limits. They rely on a database of thousands of pre-made answers to pre-thought up conversation scenarios. Every time a user writes something, the bot looks through its database for an answer. If a user's question alternate a little from the bot's script, it's followed up by a standard "I don’t understand the question" reply. It's a stone sure way to find out if that sweet girl you're talking to on Tinder is actually a human..
I've saved the most difficult post for last in this run of summer-holiday-posts. The user. There are so many ways to represent a user, so the way you draw him/her depends on your context, on what you want to achieve. Note: All the "meanings" or "moods" written under the figures are my own. You can perceive them in a different way. The perceived meaning of symbols are heavily influenced by environment and culture.