LOS ANGELES – California Watch, the largest group of investigative reporters in the state, recently delved into the credentials of California teachers and uncovered some disturbing trends.

According to its report, “Every year in California, public school administrators assign thousands of teachers to classes for which they lack the credentials or legal authorization to teach.”

A big part of the problem comes from teachers unions, which fight to keep their members employed, regardless of whether their particular skills meet student needs, the report said.

MORE NEWS: Know These Before Moving From Cyprus To The UK

“It’s hard to find a starker example of how school districts under the control or strong influence of teacher unions value the needs of adult employees over the needs of students,” CalWatchdog.com opined about the report.

California Watch cited data compiled by the state Commission on Teacher Credentialing and determined that from 2007 through 2011, one in 10 teachers – more than 32,000 employees – were instructing classes for which they did not have the proper certification to teach.

Biology teacher Charlie Parker told California Watch that four years ago, while he was working at McAlister High School in Los Angeles, he was assigned to teach U.S. History, World History and economics – subjects that he didn’t enjoy as a student thirty years ago and in which he is not well versed.

This situation was detrimental to both teacher and students. Parker said he struggled to put together lesson plans and spent his evenings trying to get a handle on the material, just like his students. Parker told California Watch that there were times when he was unable to answer his students’ questions and had to refer them to the Internet instead.

Problem worse in bad schools

The problem of misassigning teachers is especially prevalent at low-performing California schools, many of which have high percentages of Latino students who are still struggling to speak English, according to the report. Throw into the mix some teachers who lack a mastery of their subjects, and disaster is bound to ensue.

MORE NEWS: How to prepare for face-to-face classes

Steps have been taken in recent years to try and address this problem, including a 2004 class action lawsuit, Williams v. California, that charged the state with failing to ensure that all students had qualified, credentialed teachers.

However, the rate of misassigned teachers at low-performing schools continues to be high, at just over 12 percent, according to the report. Additionally, the process of monitoring teacher assignments is dense, drawn out and “paper-heavy.” This often leads to situations in which teachers are instructing classes they are unqualified to teach for months on end.

According to the report, “Research and interviews with state and local education officials suggest that staffing turnover and shortages, insufficient resources, poor planning and mismanagement contribute to assigning teachers to classes for which they lack specialized training.”

There is another side to the story.

Michael Hanson, superintendent of the Fresno Unified School District, told California Watch that misassigning teachers is “sometimes the best solution.” The report details Hanson’s line of thinking: “In the last school year, for example, scheduling conflicts led to a high school algebra teacher instructing one period of geometry, a course the teacher’s credential did not permit.

“I’m not going to find a geometry teacher who can work one period during the day,” Hanson said. “Here’s the only way I can get it done.”

Though a teacher certified in geometry may be perfectly able to teach algebra, this line of thinking, and casual flip-flopping between teachers and subjects, leads to a situation like that of Parker’s – a biology teacher trying to decipher and teach economics.

The report explains that if and when county offices of education identify misassigned teachers – which can often take up to several months – the educators have various options that range from reassignment to resignation.

The teachers unions aren’t exactly in the business of supporting teacher resignations. So instead of making sure students have qualified instructors, the schools shuffle instructors around to ensure unionized teachers keep their jobs.

That means trying to fit more square blocks into round holes, because the needs of adults are too often put before the needs of students.

“This is really about the tension between what students need every year and the adults that we’ve already hired in the system and probably have permanent (tenured) status,” said Hanson of Fresno United.