听力材料：
Listen to part of a lecture, in an education class.
So part of what teachers do is offer their students feedback or comments on their work or performance. They praise them when they do something right, or let them know if they're doing something wrong. And this feedback helpsstudents improve their work in the future.
Effective feedback, feedback that's more likely to help students improve has certain characteristics. Let's talk about two characteristics of effective feedback. One characteristic of effective feedback is that it's properly timed. Feedback should be given when students are still working on a particular task or skill and have opportunities to apply the feedback, to practice the teacher's suggestion on a similar assignment. For example, if there's an art teacher who students have been working on paintings for an assignment, she should give them feedback on these paintings while the class is still studying painting. So the students can actually try the painting techniques. The teacher recommends.
Another characteristic of effective feedback is that it focuses on student's work and not on the students themselves. When a teacher criticizes students, they might feel bad about themselves, but they won't necessarily know what to do differently. But when feedback focuses on student's work, they learn what to do in the future. For example, to go back to the art teacher, let's say one of her students does a painting and the teacher thinks the colors in the painting don't look good. Instead of telling the student, he's a bad painter, the teacher might suggest different colors to use in the next painting.
Question：
Using points and examples from the lecture, explain two characteristics of effective feedback.
