Surprise, surprise: Another analysis of teacher quality, another finding of disparities for low-income and minority students. (As faithful Gradebook readers know, we've been writing about this a lot lately.)

The latest is from The Education Trust, which found poor and minority students in middle and high schools are twice as likely as other secondary students to be taught by out-of-field teachers in English, math, science and social studies, according to its Core Problems report released this morning.

"Conversations about the achievement gap often turn too easily to what's not happening in students' homes," Ed Trust Vice President Ross Wiener said in a press release. "These data make clear that we need to put much more emphasis on what’s not happening in classrooms."

Education Trust defined out-of-field teachers as not having certification in the subjects they're assigned to teach and not having academic majors in that subject. The problem is especially bad in secondary math: 40.5 percent of math classes in poor schools are taught by out-of-field teachers; in schools with the least low-income students, the figure is 16.9 percent.

In Florida, 66.1 percent of secondary teachers in core subjects report being certified in the subject they're assigned to teach, the study shows. Teachers in only 10 other states reported having lower rates.

- Ron Matus, state education reporter