Students need many things, from visionary principals to sharp pencils. Somewhere near the top of that list should be these two words:

Black teachers.

As of 2012, 16 percent of public school students were African-American, while just 7 percent of teachers were black. To make matters worse, according to the U.S. Department of Education, black teachers are leaving their classrooms at a higher rate than any other group.

To better understand the needs of these educators, researchers at The Education Trust, a national nonprofit that advocates for vulnerable students, went on a listening tour, convening focus groups of black teachers across seven states.

"To provide voice to an often unheard group," says Ashley Griffin, interim director of K-12 research at The Education Trust. "We wanted to make sure, if we were trying to recruit teachers, that we understood why they were leaving the workforce."

Of the 150 teachers who participated, most were women (80 percent) and most (76 percent) were in the South. The vast majority — 90 percent — taught in city schools, and nearly a third had been in the classroom for more than 15 years.

The result is " Through Our Eyes: Perspectives and Reflections From Black Teachers." Below, we've highlighted a few big themes from the report and curated some of its most compelling quotes, all anonymous.

Theme No. 1: The connection

Many of the teachers interviewed spoke passionately about their work and about the need for more teachers of color, saying their black students often feel more comfortable around them than they do around other teachers.

"I think my influence on the children I teach is very important. Your home life may be rough, you know. We already know that, but you can see somebody, me, I'm just like you. And for me, I let them know personal things about myself, when I was a child, what I did ... They don't have the confidence, but they see it in you."-- Greensboro, N.C.

Or this:

"You can pull a student out of a classroom — and I've not encountered the student — but as soon as they step out and see my face, as opposed to the other teacher or instructor, they feel comfortable enough to share some things that they might not have with the teacher of a different ethnicity."-- Fayetteville, N.C.

And that sharing works both ways:

"So we can share the challenges ... with students of color. 'This is what you're going to have to deal with, but look at us. You can be successful. This is the focus you have to have.' "-- New Jersey

This connection, the teachers said, can even be a source of strength that helps them manage their classrooms:

"I didn't have to get loud or do anything. It was just, I had a no-nonsense kind of attitude, where it's a lot of nonverbal cues. 'I expect more from you.' You know, it was just, it's a different vibe than other teachers, where they kind of make excuses, and 'Oh, I can't handle you. I'm afraid of you. I want you to be my friend.' No. They're going to respect me."-- Tuscaloosa, Ala.

Indeed, new research out of North Carolina suggests that black students are less likely to be suspended from school when their teacher is also black.

Theme No. 2: The burden

For many black teachers who participated in The Education Trust's listening tour, this connection is both a blessing and a burden.

"I felt it was my obligation to teach my students, I mean my race. I knew that they will put them in a corner somewhere and just leavethem there, and I felt it was my — you know, it was my — as ateacher, I felt I had to. I had to."-- Tennessee

And that can be exhausting:

"One day I said it. I said, 'I don't think I taught today. I felt like I was a nurse, a therapist, a fan, a mentor.' I was like, 'I don't even know how I floated through this day,' I said, 'because it was Ms. H this, or Ms. H this, [or] that. Band-Aids, this, oh my goodness, my sister!' "-- Memphis, Tenn.

There's another downside. Because of their success managing students who had struggled or acted out in others' classrooms, many black teachers reported feeling pigeonholed:

"I was the only Black teacher there, but I handled basically all thediscipline problems."-- Birmingham, Ala.

Some said they had lobbied to teach more advanced courses but were told they'd be more useful teaching low-performers:

" 'You do it so well, let's just keep you here.' If I'm doing the ABCsevery day, I never really get to do anything of a higher caliber. I think a lot of times, as African American teachers, we get stuck in a certain group, because you do it well."-- Greensboro, N.C.

Theme No. 3: Bias

Black teachers consistently reported bias in their schools — from principals, colleagues and parents. Many said they feel like they work just as hard if not harder than their colleagues but get less recognition:

"I've put in a lot of work, and there are a lot of things that I'veimplemented and have shared with other people and other teachers,and then they get the credit. And I told one of my co-workers — it'sbeen recently, and she is a White coworker, and she recognized it, too — and I told her, 'It's starting to piss me off, because I'm putting in this work, and someone else is getting recognized for something that they really didn't do, or someone else is looking to be more qualified with less years and less time in the position.'"-- North Carolina

And we'll end with this:

"You don't even see what I can bring to the table ... [A]ll youdo see is that I don't belong at your table."-- Houston, TexasCopyright 2016 NPR. To see more, visit http://www.npr.org/.