Okay kiddo, let me explain what author-level metrics mean in a way you can understand.
Imagine you are in a competition with other kids to see who can draw the best picture. You draw a beautiful picture that everyone loves and gives you a sticker as a prize. This sticker is like a metric, it tells you that your picture was great and you did a good job.
Now let's say you enter another competition and draw an even better picture, but this time you don't get a sticker because the judges didn't think your picture was the best. This means that your metric or measurement of success is lower this time.
Just like in the competition, authors also have metrics to measure how their work is received by others. These metrics can include things like how many times their articles have been cited by other authors or how many times their books have been sold.
So, author-level metrics are a way to measure how successful an author is in their field based on how their work is received by others. It's like giving them a sticker for doing a good job and telling them how well their work is liked by others.