I have received a letter from my boss saying that a meeting has been arranged for this date and time, and a member of HR will be there.
That is all the letter said.
When I asked the boss what the meeting was about she explained that it is a one-on-one meeting to discuss the contract I signed and talk about the shift change. I'm confused as to why a member of HR is attending on a supposedly one-on-one meeting and no other explanation was given.
How should I prepare for this meeting?
( 5 months ago )
Is your company a union company?
If so, check if you have a right to bring a union representative the same way that your boss has someone from HR. Most likely, you do.
Because the one thing you want to avoid is being in a 2 vs. 1 situation that could turn into a "he said / she said" conflict.
Announce this before, and treat it as a perfectly normal thing. If pressed, explain calmly that since you don't know what the meeting is about, you are sure that the presence of the union rep is entirely unnecessary, but you brought him just in case, so no time is lost in fetching him if his presence should turn out to be of advantage.
That doesn't mean this is bad. It really could be entirely harmless, and the HR person might be there not to check on you, but to check on your boss. But the point is that you don't know. So better safe than sorry.
If you don't have a union rep on hand, then @Hilmar wrote a very good answer on how to prepare and behave, especially points #2 and #3.