During a recent algebra class, students at Capital High School had some questions for the teacher regarding their assignment.

"We'll ask the substitute and he'll be like, 'Well I don't know,'" Capital High School junior Rossa Moreno says. "And we're like, 'Oh, great.' That's just Capital."

Capital High School teachers racked up 938 absences over the 2009-2010 school year, according to data provided to SFR by Santa Fe Public Schools under a records request. When adjusted for enrollment, that teacher absentee rate is nearly 40 percent higher than that of Santa Fe High School, which also has significantly higher test-score rates than Capital.

The link between teacher absences and student performance isn't coincidental, according to studies done in New Mexico and other states.

The national Appleseed network compared 2009-2010 school year data from two Albuquerque high schools and found teacher attendance-rate disparities similar to those of SFHS and CHS. Albuquerque's La Cueva High School had a ratio of teacher absences to student enrollment similar to that of SFHS, while Rio Grande's teacher absence rate was similar to CHS'.

La Cueva's test results for Adequate Yearly Progress, the federally mandated testing on public school students, was in the 70-80 percent range last year, indicating that the majority of tested students showed adequate knowledge in those subjects. Rio Grande High School, with the higher rate of teacher absenteeism, had a math AYP score of 22 percent and a 33 percent score in reading.

The two sets of schools in Albuquerque and Santa Fe also parallel each other in terms of economic disparities between the student populations they serve. According to the Appleseed study, La Cueva serves a "middle class" population, while Rio Grande serves "high-poverty" kids. The most recent AYP data states that 47 percent of SFHS test-takers were "economically disadvantaged," while 84 percent of CHS test-takers met those criteria.

The disparity in test scores is not as great for the Santa Fe schools as for the Albuquerque schools in the Appleseed study. In math, 32 percent of SFHS test-takers met AYP, compared to 26 percent for CHS. Differences in reading scores were more pronounced; 58 percent of SFHS met AYP for reading, compared to 41 percent for CHS.

The gap between SFHS and CHS' test scores may widen over time, however, unless teacher absenteeism rates are brought under control. As teachers miss school and their students fall behind, the prospect of returning to class can become increasingly daunting. A 1993 study showed that teachers with low performance ratings tend to have higher rates of absenteeism than teachers rated satisfactory.

"Schools in which absenteeism is a problem essentially are potentially in a downward spiral," Raegen Miller, associate director for education research at the Center for American Progress, says.

"You can imagine that, if you have lots of teachers absent and they're not leaving behind good lesson plans, things all sort of go haywire at the school," Miller says. "If you have that kind of thing going on, it's certainly going to make the school a tougher place to work."

A lack of preparation among substitute teachers contributes to the emergence of that pattern, Miller, who has done extensive research on the issue of teacher absenteeism, explains. Oftentimes, teachers don't leave behind lesson plans for the substitutes to follow, he tells SFR.

Moreno says that students need to use computers in some classes, and teachers often forget to leave keys to the computers for the substitutes.

"Then we can't even do the work," Moreno says. "We kinda just sit there. I guess we could go to other classes and do work, but we kind of just mainly sit there."

At Santa Fe Public Schools, teachers needing substitutes have the option of using a phone- and internet-based electronic system to transmit lesson plans to substitutes, SFPS Substitute Teachers Human Resources Associate Greg Woldt tells SFR. Teachers also use that system to notify the school when they're going to be absent. Research compiled by Mary Finlayson, who studied effects of absenteeism at Cobb County School District, Ga., showed that school districts which allow teachers to call in sick through electronic systems rather than by contacting administrators tend to have higher rates of absenteeism.

One of Miller's studies finds that the average days per school year a teacher is absent is 5.13, with each teacher's absences ranging from 2.5 to eight days. At CHS, teachers were absent 11.2 full days on average, with individuals' totals ranging between one and 89 days. Finlayson's research notes that a culture of teacher absenteeism can develop at a school, influencing more teachers to play hooky, if the problem isn't addressed.

According to SFPS Records Custodian LeeAnn Archuleta, teachers are permitted six sick days and four personal days per school year, and can accumulate personal days from previous years to use up all at once. If a teacher uses all of those days and any accumulated from previous years, his or her pay is docked for additional time off, Archuleta says.

According to payroll data for school year 2010-2011, SFPS expected to spend $1.25 million on substitutes covering teachers' sick leave and $189,760 covering other leave, including professional development. Substitute teachers' pay ranges from $65-$85 per day, depending on whether they have bachelor's degrees and teaching licenses, Woldt says.

Substitute teachers don't need the same qualifications as regular teachers, and also aren't required to have specialized knowledge in the subject for which they're substituting, Woldt says. Substitutes are only required to have substitute teaching licenses, and are expected to just follow the regular teachers' lesson plans, with the idea that they don't need to understand the subject matter. This is the problem Moreno noticed in her classes. When regular teachers return, they have to go over whatever they would have done in the missed days, causing the class to get behind, Moreno says.

"Higher absenteeism redounds to the detriment of those teachers' students," Betsy Cavendish, executive director of Appleseed, says. "Learning suffers when continuity is broken by frequent substitute teachers."

Jackie Gibbs, a CHS alumna, says her educational experience was disrupted by the constant switching of teachers.

"We had, like, substitutes for our teachers the whole [last] year and different teachers coming in and out of the classroom," Gibbs says." A lot of [students] dropped out or switched schools because of how awful it was."

A 2008 study done in Wisconsin found that "students in a classroom eventually lose the desire to learn when the regular teacher is frequently absent and the delivery of instruction is by an array of substitute teachers."

While the link between large class sizes and poor student achievement has been recognized for decades, the full impact of teacher absenteeism on academic performance has been overlooked until very recently. The federal School Improvement Grant program recently began including teacher attendance as a leading indicator of school performance, signaling the arrival of the issue on education policymakers' radars.

"Especially if you're looking at chronically underperforming schools, you simply have to look at to what extent teachers are showing up, if you expect to improve schools," Miller says.