Among the many factors that influence student learning,
teacher quality is believed to be one of the most crucial.
Studies have found that various aspects of teachers and
teaching make a significant difference in student performance
(Boyd et al. 2008; Clotfelter, Ladd, and Vigdor 2007; Croninger et al. 2003; Darling-Hammond et al. 2005; Goe
2008; Guarino et al. 2006; Hanushek et al. 2005; Harris and
Sass 2007; Nye, Konstantopoulos, and Hedges 2004; Wayne
and Youngs 2003; Xue and Meisels 2004). To ensure that
all classrooms are led by teachers who are effective in promoting
student learning, the federal No Child Left Behind
Act (NCLB) of 2001 mandates that schools and districts hire
only "highly qualified" teachers, defining "highly qualified"
in terms of state certification (excluding emergency, provisional,
or temporary licenses),^{[7]}
a minimum of a bachelor's
degree, and demonstrated subject area competence.^{[8]}

This section examines indicators of teacher preparedness,
experience, professional development, salaries, and
working conditions. The major data source used here is the
Early Childhood Longitudinal Study, Kindergarten Class of 1998–99.^{[9]}
This longitudinal study followed students from
kindergarten through eighth grade and collected data from
students' teachers and schools as well as from the students
and their families. When the cohort was in grades 5 and 8 (in
2004 and 2007, respectively), ECLS-K collected data from
their teachers in each of the core academic subjects (i.e.,
reading/language arts, mathematics, and science), allowing
researchers to distinguish teachers who taught mathematics
and science from all other teachers.^{[10]}
Because the teacher
information in ECLS-K was linked to the sampled students,
the data enable analysis of whether students from different
backgrounds and with different levels of prior achievement
had equal access to high-quality and experienced teachers in
their fifth and eighth grade mathematics and science classrooms.
When possible, comparable data from the 2008 edition
of *Science and Engineering Indicators* are either cited
or included as complementary information about teachers
of mathematics and science at the middle school and high
school levels.

Researchers have often relied on indicators such as test scores (e.g., Praxis; see Gitomer 2007), education credentials, professional certifications, and teaching experience as proxies for teacher quality (Darling-Hammond 2000; Wayne and Youngs 2003). These indicators are relatively easy to measure and can be readily used to screen prospective candidates. They also align with the requirements for highly qualified teachers specified in NCLB. The following analysis examines the quality of mathematics and science teachers by focusing on the educational attainment, certification status, subject area preparation, and years of teaching experience of those who taught mathematics and science in public schools to fifth graders in 2004 and eighth graders in 2007.

Teacher quality is not limited to the characteristics examined here, however; it may include other important elements that are difficult or costly to measure, such as teachers' abilities to motivate students, manage the classroom, maximize instruction time, and diagnose and overcome students' learning difficulties. Current research on "teacher quality" is designed to yield measurable characteristics of teachers that are associated with student learning (Angrist and Guryan 2008; Boyd et al. 2008; Hill, Rowan, and Ball 2005; Goe 2008). This work is beginning and is expected to yield measures of teacher quality more directly related to student achievement than are the indicators examined here.

**Formal Preparation**

Teachers acquire a significant amount of subject knowledge
and teaching skills through formal education and certification.
Thus, teachers' level of educational attainment and
type of professional certification provide some indication
of how well teachers are prepared for their work.^{[11]}
Data on
teachers' highest degree and certification status (regardless
of the field in which the degree/certification was held) indicate
that virtually all of them had at least a bachelor's degree.
Nearly half also had a master's or higher degree, and
a majority held a regular or advanced teaching certificate
(NSB 2008).

Similar patterns are observed when the analysis focuses
on how many students are taught mathematics and science
by teachers with various levels of educational attainment and
types of certification. For example, almost all public school
fifth grade students in 2004 and eighth grade students in
2007 were taught mathematics and science by teachers who
had attained a bachelor's or higher degree (regardless of the
field in which the degree was earned), and about half of them
were taught these two subjects by teachers with a master's
or higher degree (appendix table

**Subject Area Preparation**

Adequate subject matter knowledge and skills are critical
for teachers to teach their subjects well (The Education Trust
2008; Goe 2008; Ingersoll 2003). NCLB mandates that all
students be taught by teachers who not only are fully certified
and possess at least a bachelor's degree, but also demonstrate
competence in subject knowledge and teaching. In its
2007 policy recommendations regarding STEM education,
the National Science Board (NSB) emphasized that STEM
teachers should receive adequate STEM content knowledge
that is aligned with what they are expected to teach (NSB
2007). Similarly, a report from the National Research Council
of the National Academies (2007) advocated that teacher
preparation and professional development programs focus
on boosting teachers' knowledge of science, how students
learn the subject, and methods and technologies that aid
science learning for all. However, neither NCLB nor these
reports' policy recommendations provide specific guidance
or criteria regarding "adequate" preparation to teach mathematics
and science at various grade levels.

While most states require those who teach mathematics and science at the high school level to have a degree or certification in their subject area, state laws and regulations regarding preparation of middle school teachers (eighth grade teachers fall in this group) vary, with some states allowing general education preparation and others requiring subject area preparation. As for elementary school teachers, who typically teach multiple subjects, most state policies consider teachers with a degree or certification in general elementary education to be "qualified" to teach elementary school mathematics and science (and other subjects), although some question whether elementary school teachers with general education preparation have sufficiently rigorous preparation for teaching mathematics and science (Greenberg and Walsh 2008).

Recent research efforts have focused on matching teachers' formal preparation (as indicated by degree major and certification field) with their teaching field to determine whether teachers have subject-specific preparation for the fields they teach (McGrath, Holt, and Seastrom 2005; Morton et al. 2008). Following this line of research, four levels of teachers' formal preparation for teaching mathematics and science at fifth and eighth grade levels were distinguished. In order of decreasing rigor of preparation, they are as follows:

**In-field:**Teachers who taught mathematics and had a degree and/or certificate in mathematics or mathematics education. Teachers who taught science and had a degree major and/or certificate in science or science education.**Related-field:**Teachers who taught mathematics and had a degree and/or certificate in a field related to their teaching field (such as science, science education, computer sciences). This category is omitted for teachers of science in ECLS-K because these teachers were not asked about their degrees or certificates in specific science fields such as physics, chemistry, or biology.**General education:**Teachers who taught mathematics or science and had a degree and/or certificate in general elementary or secondary education. Such teachers usually undergo some pedagogical training in mathematics and science.**Other:**Teachers who taught mathematics or science but did not have a degree or certificate in their teaching field, a related field, or general elementary or secondary education.

In-field teaching in mathematics and science was less
prevalent at lower grade levels than at higher grade levels.
For example, in 2004, about 40% of fifth grade students in
public schools were taught mathematics and science by in-field
teachers (table

Similar patterns were also revealed using the teacher data
from the 2003–04 and 2007–08 Schools and Staffing Survey
(SASS).^{[12]}
In 2003, 53% of teachers of mathematics and
67% of teachers of science in public middle schools were
teaching in field (table ^{[13]}
Partly reflecting the impact
of NCLB on teacher qualifications, in-field mathematics
teachers in public middle school increased to 64% in 2007,
representing a significant 11 percentage point increase from
2003. Seventy percent of teachers of science in public middle
schools were teaching in field in 2007, but this does not
represent a significant increase from the 67% in 2003. In
both years, between 27% and 38% of middle school teachers
were teaching mathematics and science with general education
preparation.

Moving up to the high school level, in-field teaching became more common. For example, in-field teaching in 2007 ranged from 82% of teachers of physical sciences and 88% of teachers of mathematics to 93% of teachers of biology/life sciences. The share of teachers with general education preparation declined to 3% or lower. Similar percentage ranges also were found among public high school mathematics and science teachers in 2003.

**Teaching Experience**

Experienced teachers are, generally, more effective
than novices in helping students learn (Boyd et al. 2006; Clotfelter, Ladd, and Vigdor 2007; Hanushek et al. 2005; Harris and Sass 2008; Rice 2003; Rockoff 2004; Rowan,
Correnti, and Miller 2002; Wayne and Youngs 2003).
Overall, teachers with more than 3 years of teaching experience
make up a large majority of the mathematics
and science teaching force in public schools (NSB 2008; NCES 2007a). Likewise, between 82% and 88% of public
school fifth and eighth grade students in 2004 and 2007
were taught mathematics and science by teachers with more
than 3 years of teaching experience (appendix table

**Differences in Student Access to Qualified
Teachers in Science and Mathematics**

Access to better-qualified teachers was not equally distributed
among students. In general, black and Hispanic students,
students from less-educated and low-income families,
and students with low levels of prior achievement had less
access to teachers who were highly educated, fully certified,
and had more experience and better preparation in the
subject field than their counterparts (appendix table

In eighth grade, students whose mothers had not earned a high school diploma were less likely than those whose mothers had a bachelor's or higher degree to be taught science by teachers who had a master's or advanced degree (46% vs. 57%, respectively), a regular or advanced teaching certificate (79% vs. 87%), an in-field degree or certificate (84% vs. 93%), and more than 3 years of experience in teaching science (69% vs. 83%) (appendix tables 1-12, 1-13, and 1-14). Differences existed when looking at family income as well: eighth grade students from families with incomes below the poverty threshold were less likely than those from higher-income families to be taught science by teachers with a regular or advanced teaching certificate (79% vs. 86%, respectively), an in-field degree or certificate (84% vs. 89%), and more than 3 years of experience in teaching science (69% vs. 79%). In addition, 92% of students with high achievement in fifth grade were taught mathematics by in-field teachers, compared with 76% of those with low fifth-grade achievement who had such teachers.

Teachers rely on professional development to update their knowledge, sharpen their skills, and acquire new teaching techniques, all of which may enhance the quality of teaching and learning (Richardson and Placier 2001; Davis, Petish, and Smithey 2006). During the past decade, researchers have put significant effort into identifying features of high-quality professional development programs (Banilower et al. 2006; CCSSO 2008; Clewell et al. 2004; Desimone et al. 2002; Garet et al. 2001; Hawley and Valli 2001; Harris and Sass 2007; Heck, Rosenberg, and Crawford 2006; Penuel et al. 2007; Porter et al. 2000). They have come to general agreement that professional development is most effective if it

- Focuses on subject content
- Provides an intensive and sustained approach
- Is presented in a format of teacher network, study group, mentoring, and coaching as opposed to a traditional workshop or conference
- Is connected or related to teachers' daily work
- Emphasizes a team approach and collaboration
- Provides opportunities for active learning

When professional development is conducted in these ways, teachers are more likely to change their instructional practice, gain greater subject-matter knowledge, and improve their teaching (see, for example, the sidebar "Local Systemic Change Through Teacher Enhancement Program"). Consequently, there is increased potential for the professional development to have an effect on student achievement (Correnti 2007; Darling-Hammond and Youngs 2002; Wenglinsky 2002).

Evidence from the most recent national teacher survey in 2003–04 indicates that almost all mathematics and science teachers in public middle and high schools participated in some form of professional development activities during the school year (NSB 2008). However, the programs these teachers attended consisted mostly of short-term workshops, conferences, and training sessions. In general, teachers had less exposure to professional development with features identified by research as effective in bringing about positive changes in teaching practices.

Data from ECLS indicate that in 2004, the percentage of
fifth graders whose teachers of mathematics and science reported
that they had participated in staff development related
to their subject content or pedagogy during the past school
year was 73% and 53%, respectively (table

The 2007 TIMSS provides further evidence regarding
the extent to which elementary school teachers participate
in professional development in mathematics and science (Miller et al. 2009). In 2007, the percentage of fourth graders
whose teachers participated in professional development on
various aspects of mathematics during the previous 2 years
ranged from 47% for assessment and 50% for pedagogy/instruction
to 60% for mathematics content (figure

Adequate pay is important to attracting and retaining teachers (Guarino, Santibanez, and Daley 2006). Thus, policymakers often propose increasing teacher salaries to lower attrition and improve the quality of the teaching pool, arguing that if teachers could earn higher pay both when entering the profession and over time, stronger candidates would be drawn to teaching and more effective teachers might be retained (Johnson, Berg, and Donaldson 2005; Loeb and Reininger 2004; Stronge, Gareis, and Little 2006).

According to the latest annual teacher salary survey conducted
by the American Federation of Teachers (AFT),^{[14]}
the
average salary for all public K–12 teachers in 2006–07 was
about $51,000 (AFT 2008). After adjustment for inflation,
teacher salaries grew by 2.8% from 1996–97 to 2006–07.
During this 10-year period, 18 states experienced declines in
inflation-adjusted teacher salaries.

Using data from the Current Population Survey of the Bureau
of Labor Statistics, Allegretto, Corcoran, and Mishel
(2008) compared the weekly wages^{[15]}
of full-time public school teachers with those of people working in occupations
requiring comparable education and skills, such as accountants,
reporters, registered nurses, and computer programmers.
^{[16]}
Their analyses showed that in 2006, full-time public
school teachers earned 86% as much in weekly wages as did
those in this set of comparable occupations. Furthermore,
between 1996 and 2006, the gap in weekly wages between
full-time teachers and those in comparable occupations widened
from $7 to $153, in constant dollars (figure

Poor working conditions can cause stress and dissatisfaction and may lead teachers to leave the teaching profession altogether (Hanushek, Kain, and Rivkin 2004; Hanushek and Rivkin 2007; Ingersoll 2001; Johnson, Berg, and Donaldson 2005). The working conditions that matter most to teachers include administrative leadership at their school, working relationships among colleagues, level of parental support, teaching loads, and student discipline problems (Guarino,Santibanez, and Daley 2006).

Most public middle and high school teachers have positive
perceptions about their school conditions (NSB 2008).
Such positive perceptions are also widely held among fifth
and eighth grade students' teachers. In 2004, for example, for
a large majority of fifth grade students (94%), the teachers
who taught them mathematics and science felt accepted and
respected by their school colleagues (appendix table ^{[17]}
that staff members had school
spirit (81%) and agreed about the central mission of the
school (75%); that school administrators knew the direction
of the school and communicated it to staff (81%) and were
supportive and encouraging (80%); and that parents were
supportive of school staff (70%). Furthermore, relatively
few students' teachers reported various learning and behavioral
problems among students (12%–21%). Reports from
eighth grade teachers were similar (appendix table

Positive perceptions of school conditions were less widely
held among teachers of minority, socioeconomically disadvantaged,
and low-achieving students. For example, fifth
grade students whose mothers had less than a high school
education were less likely than students whose mothers had
a bachelor's or higher degree to have teachers who described
parents in their school as "supportive" (61% vs. 82%, respectively)
(figure