Decentralization, Teacher Quality, and the Education of English Learners:

English learners are entitled to participate meaningfully and equally in educational programs. The Every Student Succeeds Act (ESSA) includes provisions to ensure success for all students, including English learners. However, the federal government does not prescribe specifically how states should meet these provisions; instead, it is the responsibility of states to develop respective plans of action. This decentralization means that states play a primary role in setting policy for teacher credentialing. In this paper, we address the following question: Do state education agencies effectively prepare teachers of ELs? We reviewed the teacher credentialing requirements to teach classified English learners in bilingual education, English language development, and sheltered Education Policy Analysis Archives Vol. 29 No. 100 2 English immersion settings, as well as the professional teaching standards for reference to culturally and linguistically diverse learners across the 50 states and the District of Columbia. We found inconsistencies across the US with regard to the education of classified English learners and document wide variation in teacher certification for working with English learners. We highlight implications for policy and teacher preparation.

preparation teachers will receive. Thus, in this study we use SEA requirements for teacher certification as a proxy for teaching preparation, with the assumption that teacher preparedness is correlated with teacher effectiveness (Darling-Hammond et al., 2005). In order to meet the requirements of Casteñeda v Pickard (1981) teachers in bilingual education, English Language Development (ELD) 3 , Sheltered English Instruction (SEI) and any mainstream setting in which ELs are educated, must be adequately trained to meet students' needs. Through an analysis of the documents that SEAs have included on their official web pages, we explore preparation requirements for teachers of ELs in various settings (bilingual education, ELD, SEI, and mainstream classrooms). 4

Theoretical Framework
This paper is based on the argument that teachers are an important resource in providing educational opportunities to ELs, and that establishing specific requirements for teacher credentialing falls squarely on SEAs. As the leading educational organizations in their states, SEAs convey educational priorities and commitments to populations of learners, including ELs.

Review of Literature
Indoctrination into the teaching profession requires mastery of core content and development of pedagogical skills (Darling-Hammond et al., 2005). Effective teaching is an important factor in student achievement (Darling-Hammond, et al., 2005;Goodson, et al., 2019) and in providing equitable educational opportunities to ELs regardless of their program placement (see e.g., Faltis & Valdés, 2016;López et al., 2013;López & Santibañez, 2018;Lucas et al., 2008). For teachers of ELs this includes a depth of knowledge including, but not limited to, linguistics, an understanding of first and second language acquisition, a firm foundation in curricular standards, and a solid collection of research-based and culturally-relevant instructional tools for teaching ELs (Valdés et al., 2013). Most recently, pedagogy for ELs has focused on linguistically and culturally responsive pedagogical practices (Faltis & Valdés, 2016;Lucas & Grinberg, 2008;Lucas et al., 2018) including translanguaging (Daniel & Pacheco, 2015;García et al., 2017;Menken, 2013), 3 Henceforth in the paper we use ELD to refer to English Language Development and English as Second Language (ESL) instruction. While we recognize that the majority of states continue to use "ESL" to refer to English language instruction for designated ELs, we believe that ELD is a more accurate label as ESL assumes English is the second language a student is learning and it also does not account for the experience of simultaneous bilinguals. Thus, with the exception of citing state documents or credentials that explicitly use "ESL", ELD will be used moving forward. 4 Although research suggests that bilingual education is the most effective program (Collier & Thomas, 2017;Wright, 2019, etc.), it is beyond the scope of this paper to argue for any particular program. Instead we analyze states' requirements for teacher certification for each language program. representation in the curriculum (Clark et al., 2016), anti-racist TESOL practices (Motha, 2014), and general recognition of students' bilingualism as an asset (Souto-Manning, 2016).
In addition to strong content and pedagogical foundations, educators of ELs benefit from teacher preparation that includes field-based experience with ELs (Bollin, 2007;Fitts & Gross, 2012;Pappamihiel, 2007). Field experiences can further help teachers recognize and capitalize on students' cultural and linguistic capital (González et al., 1995;Smolcic & Martin, 2019). Indeed, teachers' beliefs about language and their students' experiences affect their practice (Brousseau et al., 1988;Costa et al., 2005;Meskill, 2005). Unfortunately, research has documented that teachers hold deficitbased misconceptions on ELs' knowledge and ability to learn (Faltis & Valdés, 2016;Harper & de Jong, 2004). As a group, US teachers remain underprepared to teach ELs (Gándara et al., 2005;Karabenick & Noda, 2004;Reeves, 2006) and it stands to reason that teacher preparation is a space to address teacher dispositions, knowledge, and practice. Yet only 20 SEAs currently require EL teachers to hold special certification (López & Santibañez, 2018).

Educational Programs for ELs
As illustrated in Table 1, ELs are typically taught in one or a combination of the following language instruction educational programs: bilingual education 5 , English Language Development (ELD) Sheltered English Instruction (SEI), and mainstream. In this section, we introduce each language instruction educational program along with its requisite teacher preparation. For clarity, we begin with what all teachers, including mainstream teachers, 6 should know and then discuss the additional requirements for bilingual education and ELD specializations.
Contemporary scholars have stressed the importance of preparing all teachers to be able to make content understandable to ELs and support ELs' linguistic development throughout the content areas (Bunch, 2013;Coady et al., 2016;de Jong & Harper, 2005;Faltis & Valdés, 2016;Haas et al., 2016: Turkan et al., 2014. Faltis and Valdés (2016) state that all teachers must have the "knowledge, skills and inclination" to teach ELs (p. 686). Consistent with this, Galguera (2011) asserts that teachers must have pedagogical language knowledge and skills to teach the growing number of ELs in US schools. Including ELs in state teaching standards for all teachers may be one way to ensure at least minimal preparation. Implementing SEI credentials for all teachers is another way to ensure teachers have at least the minimum pedagogical expertise necessary to teach ELs. SEI teachers are considered content-area (e.g., ELA, mathematics, science) specialists, who help ELs develop the English language in specific content areas. This suggests that SEI teachers will have additional training beyond the general education or content knowledge and pedagogy, which will include strategies for supporting ELs (Short et al., 2011). 5 Wright (2019) identifies five basic programs that fit under this umbrella: heritage language, bilingual immersion, dual language, and developmental bilingual programs all aim to support the continued development of bilingualism and biliteracy. Heritage programs enable students who have acquired English to maintain proficiency in their heritage languages, bilingual immersion programs are designed for English proficient students and develop bilingualism and biliteracy in the target language (i.e., French, Spanish, etc.). Dual language programs combine ELs from one language group and fully English proficient students with the goal that each group will become bilingual and biliterate. Similarly, the goal of developmental bilingual programs with groups of ELs who speak the same heritage language is bilingualism and biliteracy. 6 A general elementary education or middle/secondary content teacher in a classroom where the language of instruction is English. While it is important to prepare all teachers with knowledge and skills to make content understandable and promote language development in the content areas, research has shown that simply preparing all teachers with this knowledge and skill set is insufficient (e.g., see López et al., 2013). In fact, ELs' achievement is optimized when all teachers are trained and ELs receive services from teachers who hold specializations in bilingual education and/or ELD (López & Santibañez, 2018). These specializations provide teachers with a depth of knowledge and skills to teach ELs beyond what is expected of mainstream teachers (Faltis & Valdés, 2016;Menken & Antuñez, 2001). ELD teachers must understand the connections between first and second language teaching and learning and have the pedagogical expertise to implement an ELD curriculum that supports the development of the English language. Additionally, bilingual education teachers must have this extensive knowledge and pedagogical expertise in English and the heritage language, as well as in translanguaging/multi-languaging and multiliteracies (Aquino-Sterling & Rodríguez-Valls, 2016;Garcia & Wei, 2014;Lavadenz, 2019;Menken & Antuñez, 2001). Although research has shown that instruction by specialists combined with the preparation of all teachers has resulted in positive outcomes for ELs, problematically, only 20 states require specialist certification for teachers of ELs (López & Santibañez, 2018). The lack of requirements for specialist certifications is highly questionable given federal laws and policies that purport to protect the rights of ELs to resources necessary for educational success.

Decentralization of Federal Policies to Protect Equitable Education of ELs
Under ESEA Flexibility (2012)(2013)(2014)(2015) and ESSA (2015-present) the federal government ceded the implementation of policies that protect ELs' rights to an equitable education to SEAs and LEAs, which has resulted in a highly problematic, uneven implementation of federal policy (López & Santibañez, 2018;Morita-Mullaney & Singh, 2019). For example, states with established EL populations are likely to have more expertise than states in which the population of ELs have only begun to grow (Arias & Markos, 2016;López et al., 2013). SEAs also may differ in their "institutional will" (Garcia et al., 2009, p. 12). For example, three states (AZ, CA, and MA) effectively banned most forms of bilingual education and became English only states in the early 2000s. California and Massachusetts eventually overturned their English only policies via Proposition 58 (2016) and the Look Act (2017). Florida, Arkansas, and Virginia attempted to bypass ESSA's provision that "states make every effort" to develop first language assessments (Mitchell, 2017). Villegas and Pompa (2020) found such inconsistencies from state to state that it was impossible to fully interpret the progress of ELs or to compare EL progress between states. Obscuring the progress of ELs serves to shroud SEA and LEA progress on an important ESSA requirement: that all students are taught by qualified teachers (Casteñeda v Pickard, 1981;ESSA, 2015).

The Present Study
Our overarching question was, Do State Education Agencies effectively prepare teachers of ELs? To address this question, we operationalized teacher licensure as a proxy for teacher preparation and engaged in a document analysis (Bowen, 2009) that was guided by each of the following research questions: 1. Does the SEA have certification requirements (i.e., ELD, bilingual education, or SEI) specific to working with ELs and, if so, what are the requirements? 2. Does the SEA address ELs in their professional teaching standards for all teachers, and, if so, how?
We examined certification 7 requirements to teach in bilingual education, ELD, and SEI classroom settings in all 50 states and the District of Columbia (D.C.). We specifically selected these certifications as these are the classroom settings where by definition classified ELs are legally entitled to instruction that is designed with their cultural and linguistic strengths and needs in mind. Because ELs are often placed in mainstream classrooms (Lucas et al., 2018;Villegas, et al., 2018), we included Research Question 2 as a means of examining if mainstream teachers are required to be at least minimally trained to support ELs.

Methods
Given our interest in how states are meeting federal mandates, our primary data sources were the documents that states have made public on official SEA web pages. Specifically, we conducted a document analysis (Bowen, 2009) of documents that detailed whether SEAs mandated an approved program for certification in bilingual education, ELD, or SEI, or in the event that an approved program was not required, the specific components (i.e., coursework, practicum, exam, language proficiency) for the credential. We also conducted a document analysis of each SEA's professional teaching standards for all teachers to understand, how if at all, the SEA's published teaching standards relate to teaching ELs. It is beyond the scope of this study to verify program quality or the degree to which the states meet standards.

Data Sources
We restricted our sample to documents and information publicly available on respective SEA websites. Our decision to analyze this information stems from documentary research which suggests that documents are "socially constructed" (McCulloch, 2004, p. 40). We posit that a SEA's priorities are conceptualized in its credentialing policies and, by extension, what information is readily available regarding such policies. We assessed the original purpose of each document to determine the reason it was initially produced (Bowen, 2009), selected documents that specified certifications available in the state, laws and regulations regarding teacher certification, and Professional Teaching Standards. If necessary, we also examined additional publicly available documents (described in procedures). We downloaded all documents as PDFs between October and December 2019. See Appendix A for a complete list of all DOE websites as well as respective documents and information examined.

Procedures
Once our data set was assembled, we used a systematic process, document analysis (Bowen, 2009), to evaluate our selected documents and generate empirical knowledge (Corbin & Strauss, 2008) on SEA credential policies. Our document analysis followed a multi-step review process where we would classify the credential(s) available in a SEA (e.g., bilingual education, ELD, SEI; see Table 1) and then determined whether the credential(s) was mandatory for working with ELs and the respective requirements to earn the credential(s). During this multi-review analytic process, we followed Tight's (2019) record keeping procedures: record details of document reviewed; log the primary document contents and details of other relevant documents included in analysis; and record respective opinions of the documents.
First, we randomly assigned each of the authors a group of SEA documents to review independently. During this first round of document analysis, an author independently coded for credential classification, whether the credential was mandatory (yes or no), and then detailed the respective requirements. This process was then repeated for each SEA document, independently, by a second author. We held multiple two-hour meetings to compare findings and note any questions or discrepancies. Discrepancies were reviewed independently by a third author. Following this third review, we met again as a group to validate documents and findings. If there was confusion about data from a state website (e.g., a lack of clarity of documents or inability to find documents) we could not resolve, we consulted additional web sources (e.g., ELD Program Guidance or other SEA regulations), and documented each of these occurrences 8 . In line with Tight (2019), we documented all independent reviews and group discussions in a dedicated recordkeeping spreadsheet.
We established a procedural protocol to determine a) if the credential was available as standalone certification; b) if there was also an option to add the credential as an add-on endorsement; and c) the requirements for the credential based on the following main criteria: completion of an approved program, passing of a content exam, completion of coursework, completion of a practicum, language proficiency. 9 The procedural protocol guiding our document analysis is illustrated in Appendix B; this protocol was followed during each round of the review process. To address Research Question 2, following the same four-step protocol, we analyzed each SEA's professional teaching standards and evaluation rubrics for reference to the instruction and assessment of culturally and linguistically diverse students. We searched each document using the following keywords and phrases: diverse / diversity 10 , cultural / culture, language / linguistic and for specific reference to ELs (ELs) 11 and English language. Specific examples of keywords and phrases we included and omitted are listed in Appendix C. During a third round of document analysis, we searched for references to all, each, and every student, which we included in the diverse / diversity category.

Findings
Within the context of understanding teacher preparation for ELs, it is important to acknowledge that teacher preparation, as a whole, remains relatively inconsistent across the United States (Goodson et al., 2019;Sampson & Collins, 2012). For example, while most SEA sanctioned pathways to a teaching certification require that teachers complete a state-approved program, some SEAs offer alternative pathways. Regardless of the pathway, receipt of a certification requires teachers to have earned a bachelor's degree, have demonstrated mastery of content to be taught (generally through a standardized test), and have undergone some pedagogical training. Our analysis of credential requirements 12 and professional teaching standards across all SEAs illustrates great variation with regard to the preparation of teachers to educate ELs. For example, only 24 SEAs offer a bilingual education credential and within 45 SEAs ELD credentials can be earned as either a standalone certificate or an add-on endorsement. These findings highlight a number of issues in the variability between SEA teacher credentialing requirements that stem from decentralization of teacher quality standards. Our findings are presented below, disaggregated by classification (bilingual education, ELD, SEI). First, we examined the credential availability across SEAs. Second, we described the credential requirements. Finally, we detailed alternative pathways and/or unique requirements offered by some SEAs.

Bilingual Education Credential
Bilingual education is a broad umbrella for a variety of language instruction education programs and there is clear variation among these programs (Wright, 2019). Bilingual education credentials are only available in 25 SEAs. Eight of the 10 SEAs with 10% or more ELs offer this credential (with Florida and Kansas as exceptions). In contrast the bilingual education credential is noticeably absent from states with fewer than 6% ELs (with Vermont as an exception). Figure 1 illustrates the distribution of bilingual education credential availability by EL population density.

Figure 1
Bilingual Education Credential Availability by EL Population Density 12 Henceforth in the discussion we use credential requirements as an umbrella term to refer to both standalone certification and add-on endorsement.
Given the wide variation in bilingual education program models (Wright, 2019), it is interesting that our analysis suggests that only Oregon includes both a bilingual education endorsement and a dual language endorsement specific to native language instruction and dual language settings, respectively. Regardless of the bilingual education program model, both content (ELA, mathematics, science, social studies, etc.) and English language development are integral to the bilingual education classroom. Thus, it is unsurprising that we found 19 of the 24 SEAs offer an add-on bilingual education credential requiring teachers to hold a primary certification in elementary education, early childhood education, or a middle/secondary content area; only three SEAs (Alaska, Idaho, and New Mexico) offer the bilingual education credential as both a standalone certificate and add-on endorsement. Table 2 displays the distribution of standalone and add-on availability across SEAs.
. Table 2 Bilingual and ELD Credential Availability Disaggregated by SEA The -symbol indicates missing data Of the SEAs that offer an add-on bilingual endorsement, eight (Alaska, Idaho, Minnesota, New Jersey, Ohio, Utah, Washington, and Wisconsin) require completion of an approved program. The remaining 15 SEAs include one, a combination, or all of the following: state bilingual education assessment, TESOL Praxis, coursework, practicum, demonstration of additional language proficiency and/or demonstration of English language proficiency. These requirements are displayed in Table 3. When coursework or a practicum is required, semester credits and field experience hours vary from 12-20 and 45-100, respectively. Variations for credentialing in these SEAs is problematic considering research that suggests the importance of a rigorous specialist program (López & Santibañez, 2018;Menken, 2001), which includes fieldwork (Fitts & Gross, 2012).
Some SEAs have unique requirements. For example, although Iowa does not have a bilingual education credential, it requires that teachers hold an "authorization" to teach in a language other than English. Other SEAs have interesting stipulations attached to the bilingual education endorsement. For example, in Nebraska an ELD certification/endorsement is required before being able to add a bilingual endorsement and in New Mexico teachers with an ELD credential (standalone certification or add-on endorsement) only need to complete six credit hours of coursework (non-ELD credentialed teachers must complete 12 credit hours) in order to earn the bilingual education add-on endorsement. Although North Carolina offers a bilingual education certificate, it is limited to grades Kindergarten through six. Utah offers two pathways to earn bilingual education certification: completion of a state approved program or a combination of university courses and attending the annual Utah Dual Language Instruction Institute. It is worth mentioning that some SEAs have additional or designated bilingual education endorsements for Native American and Indigenous languages. Specifically, New Mexico, North Dakota, and Washington hold bilingual education endorsements in Native American/Indigenous languages and, while not endorsements, Alaska, Montana, and North Dakota require courses specific to Native American and/or multicultural education in their approved teacher certification programs.

ELD Credential
ELD classrooms provide ELs with curricular and instructional practices that focus specifically on the English language. All 51 SEAs offer an ELD credential. This is where uniformity ends. For example, while the ELD certificate was most often referred to as an ESL Certificate/License, some SEAs used Cultural and Linguistic Diverse (Colorado) or English as a New Language (Illinois, New York) as the name of the certificate. We also found that only 30 SEAs offer ELD as a standalone certification (where the ELD teacher does not need another primary certificate) and 19 SEAs require teachers to hold a primary certificate in elementary education, early childhood education, or a middle/secondary content area to which they can add an ELD endorsement 13 ; this distribution is illustrated in Table 2 and also by EL population density in Figure  3. Arguably, a standalone certification is a more specialized license as the sole focus in this pathway is ELD content and, because it is a standalone certification completion of a full program, it is necessary to earn the certification. In contrast, an add-on ELD endorsement is earned on top of general education content, and as illustrated in Table 4, has a wide range of requirements across SEAs to earn said endorsement. We initially suspected that perhaps the availability of the standalone certification vs. add-on endorsement might be related to geographic concentration of ELs: on one hand, SEAs with large concentrations of ELs might only offer the add-on endorsement as a way to make the certification more accessible to more teachers and, on the other hand, SEAs with large concentrations of ELs might have the standalone as a way to maintain integrity with the certification via more robust training. When examining the availability of standalone certification and the add-on ELD endorsement in Figure 2, however, there does not seem to be a geographic or demographic pattern for the distribution.

ELD Standalone Certification Availablity by EL population density
Further, 45 SEAs allow teachers to become ELD credentialled with only an add-on endorsement, 10 of which only require passing a test to earn the endorsement 14 . When coursework or a practicum is required, semester credits and field experience hours vary from 12-30 and 25-150, respectively. The information regarding tandalone certification and ELD add-on endorsement, as well as distribution of the ELD add-on endorsement requirements are displayed in Table 2 and  Table 3. The wide variation in requirements is worrisome, yet unsurprising given that research has demonstrated that majority of teachers who work with ELs have insufficient preparation (Ballantyne et al., 2008;Gándara et al., 2005;Karabenick & Noda, 2004;Herrera & Murray, 2006;Turkan et al., 2014). This wide variation in requirements is particularly problematic given that research suggests that access to consistent and quality ELD instruction is necessary in order for ELs to be effectively supported (Hass et al., 2016).
Some SEAs also include additional regulations. For example, Delaware and New Jersey explicitly state that teachers must meet an English proficiency requirement to earn an ELD certification (standalone or add-on). Some SEAs offer multiple pathways for the add-on ELD endorsement. For example, in Hawaii an add-on ELD endorsement can be earned by either meeting coursework requirements or by passing the Praxis, and in Kansas a teacher can either complete an approved program or pass a test. Similarly, New Mexico allows teachers to complete 24-36 credits or complete 12 credits and pass the subject matter test; regardless of the pathway, New Mexico requires that at least six of the credits are taken in a non-English language. South Carolina explicitly states that earning an ELD add-on endorsement by exam is not an option; however, the practicum can be waived if a teacher has one year documented of "successful teaching".
In addition to the traditional routes to certification/endorsement, it is worth mentioning that a few SEAs have emergency pathways leading to ELD credentialing. Five SEAs have "emergency pathways" to earn an ELD certification, however this certification is non-renewable. For instance, Ohio offers a "supplemental ESL licensure option" which is valid for one year and requires only a test, and Virginia has an alternative route where teachers can teach ELD provided they have a bachelor degree and 24 credits of relevant coursework. Finally, Illinois is unique in that it distinguishes between an English as a New Language (ENL) certificate and an ESL certificate; the former is an ELD certificate for an English only setting and the latter authorizes teachers to use a student's native language. It is also worth noting that Kentucky and Louisiana SEA websites had limited information available and so add-on information was gathered by examining university websites to determine the credit requirement information.  Note: 1 Program refers to completion of a state approved program that includes coursework and, typically, fieldwork; 2 Coursework refers to courses taken independent of completing a program or being a matriculating student; + Kentucky and Louisiana DOE websites had limited information available and so add-on information was gathered by examining university websites to determine the credit requirement information. The -symbol indicates to missing data.  Note: 1 Program refers to completion of a state approved program which includes coursework and, typically, fieldwork; 2 Coursework refers to courses taken independent of completing a program or being a matriculating student; + Kentucky and Louisiana DOE websites had limited information available and so add-on information was gathered by examining university websites to determine the credit requirement information.
The -symbol indicates to missing data.

SEI Credential
The SEI model employs pedagogical practices intentionally designed to support ELs' access to "core" curriculum (i.e., English, mathematics, the sciences, and the social studies) and the development of content-area English. Student composition in SEI classrooms can vary from all ELs to a combination of ELs and students who are proficient in English. Due to the restrictive language policies that banned bilingual education, a mandated SEI endorsement is required as part of the state approved general education program for all content-area teachers (e.g., early childhood education, elementary education, middle/secondary content, special education) in Arizona, California, and Massachusetts. Likely due to geographic proximity, Nevada has also begun to phase in an SEIequivalent endorsement requirement for early childhood education and elementary education (2020) and for middle/secondary content teachers (2021).
In Arizona and California, the SEI endorsement is earned by successful completion of one course; teachers in Massachusetts can earn SEI endorsement by taking a course or by passing a state SEI subject test. Arguably, one separate course focused on ELs does not provide teachers with the requisite knowledge to meet the needs of this growing population of students (de Jong et al., 2013;Flynn & Hill, 2005). Given that the SEI credential is limited to just four states, we focused our final analysis on documents that might impact teacher preparation of mainstream teachers.

Professional Teaching Standards
According to recent data, ELD and bilingual education teachers make up only 2% of elementary and secondary teachers (NCES, 2016), only 20 states actually require ELs to be taught by teachers with either of these endorsements (López & Santibañez, 2018), and only four SEAs require SEI endorsement. Thus, the majority of ELs experience a good portion of their education in a mainstream classroom. Arguably, even ELs who are placed in bilingual education and SEI program models will be in mainstream classrooms at some point as they become increasingly proficient in English. Indeed, under Title VI (OCR, 1964, 1970 ELs should not be segregated from their fully English proficient peers. Thus, while mainstream teachers are not expected to be specialists in bilingual education or ELD, they must be able to provide access to the full curriculum and support content-area literacy development for ELs. In order to understand how SEAs hold mainstream teachers accountable for educating ELs, we examined professional teacher standards for references to language suggesting attention to ELs.
All 51 SEAs have some form of professional teacher standards, typically referred to as "professional teaching standards" or "teaching performance standards". We analyzed the professional standards for references to diverse / diversity / all, cultural / culture, language / linguistic, and ELs / English language. We found that all 51 SEAs reference diverse / diversity / all, 44 SEAs reference culture / cultural, 36 SEAs reference language / linguistic, yet only 21 SEAs explicitly reference ELs / English language. Of the diversity / diverse / all category, 10 SEAs use all, each or every instead of diverse.
Generally, reference to these terms appear in a hierarchical trend such that if a document referenced ELs / English language, then language / linguistic, cultural / culture, and diverse / diversity / all were also referenced. Similarly, if explicit reference to ELs / English language is not included, but language / linguistic is referenced then generally cultural / culture and diverse / diversity is also included. When neither ELs / English language nor language / linguistic is referenced, if cultural / culture is referenced then typically diverse / diversity / all is also referenced; finally, there are a number of SEA standards that address the diverse / diversity / all category, but do not reference any of the other categories. This information is displayed in Table 5. New Mexico is unique in that it prefaces each standard with the statement that "These standards refer repeatedly to all students. These references really do mean all students and the multiple strengths, challenges and backgrounds that each student brings to the classroom. All students include, but is by no means limited, to English Language Learners, students with special learning needs, and students of all races, ethnicities, cultures and socioeconomic circumstances." There is clear variation in language used and how needs of ELs are referenced across SEA professional teaching standards.

Discussion
According to federal policy (ESEA, 1965;ESSA, 2015;OCR, 1970) all students are entitled to quality and appropriate instruction. One essential element in providing this type of instruction is a well-prepared teacher (e.g., Cloftfelter et al., 2010;Darling-Hammond et al., 2005;Lavery et al., 2018;Lee, 2018). Our findings suggest that the current shortages of bilingual and ELD teachers (only 2% of all elementary and secondary teachers) will likely continue with only 24 SEAs even offering a bilingual education credential and 19 SEAs requiring teachers to hold a primary certificate before being eligible to earn an ELD credential.
Research has also demonstrated that the large majority of teachers who work with ELs have insufficient preparation (Ballantyne et al., 2008;Herrera & Murray, 2006;Karabenick & Noda, 2004). This lack of preparedness makes sense given our analyses which illustrate that only eight states require the completion of an approved program for bilingual education credentialing. And, in 10 SEAs an ELD credential can be earned by merely passing a test. Consistent with Villegas and Pompa (2020), our analysis of SEA documents for type of teacher preparation provides evidence of wide variation of teacher preparation across state programs. It further highlights a distinct disconnect between federal policies, which themselves are problematic in that they do not specify minimal teacher preparation working with ELs, and individual states' implementations of these policies. We discuss these issues below by framing our discussion around the research questions within the context of policy decentralization that leaves the interpretation and implementation of federal laws protecting ELs to the states.

How Do Federal Laws/Policy Impact Teacher Preparation?
Federal laws (OCR, 1964;1970) and subsequent case law (e.g., Casteñeda v Pickard, 1981;Lau v Nichols, 1974) protect the rights of ELs, yet laws and policies governing the education of ELs have always been shaped by the political times and political will (Crawford, 2004;Gándara & Escamilla, 2017;Ovando et al., 2011). The language of Bilingual Education Act itself (1974) was grounded in language remediation for ELs, rather than on bilingualism and biliteracy, and subsequent authorizations became increasingly fixed on the development of English as quickly as possible. Even as research has shown that bilingual education programs hold the most promise for English learners, federal laws and policies promote programs that focus solely on English development rather than bilingualism. For example, the discontinuation of Title VII that competitively funded bilingual programs, and the transfer of funding to Title III, which is firmly situated in the development of English has negatively impacted the development of bilingual education programs. NCLB and ESSA regulations that require accountability measured in English have also had consequences for bilingual education programs and teachers. The lack of bilingual education programs and teachers places the opportunity to become a bilingual education teacher in a downward spiral. Without high quality bilingual programs that foster bilingualism and biliteracy, the potential pool of teaching candidates is reduced. As Gándara and Escamilla (2017) explain, if the federal government promoted bilingual programs, then there would be funding for bilingual education teachers.
The Casteñeda (1981) decision specifies that ELs must receive instruction within programs that are supported by research, sufficiently resourced (including effectively prepared teachers), and evaluated to show effectiveness. ESSA (2015) requires SEAs and LEAs to report academic scores disaggregated by subgroups, which would presumably show ELs' progress and needs. ESSA (2015) also transferred accountability for ELs' progress in developing English proficiency from Title III to Title I, thus holding SEAs, LEAs and individual schools accountable for this progress. ESSA, however, also transferred the responsibility of meeting the civil rights of ELs to individual states, which has resulted in vast inconsistencies across and within states (Villegas & Pompa, 2020).

How Does State Interpretation of Federal Mandates Impact Teacher Preparation?
In this study, we used teacher credentialing as a proxy for preparedness. We discuss the state interpretations of federal mandates with regard to specialists (bilingual education, ELD, and SEI) (research question 1) as well as with regard to all teachers (research question 2). In both these areas SEAs vary widely in their teacher credentialing requirements.
Although scholarship details the complexity of content and pedagogical expertise necessary for teaching ELs (Brousseau et al., 1988;Clark et al., 2016;Costa et al., 2005;Daniel & Pacheco, 2015;Faltis & Valdés, 2016;;García et al., 2017;González et al., 1995;Harper & de Jong, 2004;Lucas & Grinberg, 2008;Lucas et al., 2018;Menken, 2013;Motha, 2014;Souto-Manning, 2016;Smolcic & Martin, 2019;Valdés et al., 2013), not all states even require the completion of an approved program for either bilingual education or ELD credentialing. It is highly problematic that with the potential of bilingual education teachers to help close the gap between ELs and their fully proficient peers (August & Shanahan, 2006;Collier & Thomas, 2017;Goldenberg, 2013;Thomas & Collier, 1997), only some SEAs offer bilingual credentialing and within these SEAs, credentialing requirements vary substantially. Further for most of these SEAs, bilingual education is an add-on license and only eight states require that bilingual education teachers complete an approved program. The remaining states require variable preparation, which can consist of no more than successfully passing a test (see Table 3). Only 13 states require demonstration of proficiency in a non-English language even though bilingual education credentials allow teachers to deliver instruction in a language other than English, and thus it would seem logical that a required component of earning this credential should include demonstration of language proficiency in both English and the non-English language. Arguably, a language proficiency requirement adds additional rigor to a bilingual education credential, whether it be standalone or add-on.
Considering that research suggests the role of the ELD specialist is critical for educating ELs (López & Saltibanez, 2018), our findings showing the variability of the preparation of ELD teachers is concerning. All 51 SEAs offer a credential for ELD instruction, yet here is where similarity essentially ends. For example, the lack of clarity regarding ELD endorsement requirements in 19 SEAs clouds the effectiveness of the preparation of teachers in ELD content and pedagogy. Only 30 SEAs offer the ELD credential as a standalone certificate, and each of these also accept an add-on endorsement. In 10 states teachers can earn an ELD endorsement simply by passing a test, which is inconsistent with research on teacher preparation (Lucas & Grinberg, 2008;Valdés et al., 2013), is unlikely to result in teachers who can meet the needs of ELs (de Jong & Harper, 2005;de Jong et al., 2013;Harper & de Jong, 2004), and is in direct conflict with OCR (1970) andESSA (2015) requirements that teachers have sufficient pedagogical expertise to successfully meet the educational needs of ELs. Only 12 of the SEAs who accept the add-on endorsement require the completion of an approved program. This requirement presents a double-edged sword for SEAs and teachers. ELD is a content-based credential, and is thus similar to English language arts, mathematics, and so on, suggesting the need for a rigorous specialized program for ELD teachers (see e.g., Faltis et al., 2016;Goldenberg, 2013;Valdés et al., 2013). Yet, completion of a state-approved program creates a financial burden on the ELD teacher who must complete two programs (primary certification and ELD endorsement). This double financial burden also likely contributes to the shortage of ELD teachers. Thus, SEAs seem to be forced to choose between rigor and practicality. However, these SEAs and SEAs may find themselves without sufficient numbers of prepared ELD teachers. It makes sense that the practical problem of ELD teacher shortages may result in 'fast-track' options to meet the demand. Interestingly, of the 12 SEAs that have the option to earn an add-on ELD endorsement via a test, only four of these states currently have a teacher shortage for ELD teachers (Cross, 2017). Of the nine states with over 10% ELs, four currently have an ELD Teacher shortage and three have a bilingual education teacher shortage; none of these states have an "emergency" or "fast-track" option to earn endorsement. Additionally, as illustrated in Figure 3, we did not find any demographic patterns corresponding to availability of the standalone certification vs. add-on ELD endorsement. Clearly as states grapple to meet the needs of growing numbers of ELs and their responsibility to ensure effective teacher preparation, SEAs will need to establish long-term solutions to adequately prepare specialists to work with ELs.
It remains highly problematic that SEAs do not differentiate between teachers who have earned a credential (standalone certification or add-on) by completing an approved program and those that have earned an endorsement by other less rigorous means. The inconsistencies in teacher preparation and accountability reporting make it impossible to compare ELs progress from state to state, and thus shroud program and teacher effectiveness for ELs, which is highly inconsistent with the second and third prongs of Casteñeda.
SEI endorsement is one way to ensure that teachers receive at least some preparation to teach ELs. However, SEI is mandated in only four states only (Arizona, California, Massachusetts, and Nevada) and the required training to earn an SEI endorsement is limited. In Arizona, California, and Massachusetts, the SEI mandated credential is likely a result of long-standing English Only instruction policies (Gándara & Hopkins, 2010). As such, these states have required mainstream teachers to receive specific training to teach ELs (Casteñeda v Pickard, 1981;Echevarria et al., 2013). These restrictive (and racist) language policies, which are still in place in Arizona, were only lifted in in California (Proposition 58) in 2016 and in Massachusetts (LOOK Act) in 2017.
How are SEAs preparing all teachers to teach ELs? (research question 2). Presumably, SEA professional teaching standards are the guiding documents for teacher expectations, including how both pre-service and in-service teachers are evaluated. Although research is clear that ELs benefit when all teachers have been prepared to teach them (López & Santibañez, 2018), for the most part SEA professional teaching standards remain murky with the regard to the preparation of mainstream teachers. Alarmingly, only 21 SEAs explicitly reference ELs or English language in their standards and only 36 SEAs have any reference to language or linguistic.
While the professional teaching standards in nearly all SEAs acknowledge the needs of diverse students or all students in some way, the robustness and specificity of these standards is variable. That is, diverse students or all students may be threaded throughout state standards and accompanying rubrics, or they may be only mentioned once. Additionally, although referencing all or diverse students may be a step in considering the wide range of student needs, we question the teachers' preparedness to meet the specific cultural and linguistic needs of ELs if this language is not explicitly included in the professional teaching standards. Lack of explicit standards for teaching ELs devalues the educational needs of ELs across all classroom spaces. It also raises concerns about the quality of instruction ELs receive when they are in mainstream classrooms in which they are frequently placed (Harper & de Jong, 2004;Lucas et al., 2018;Villegas et al., 2018). Further, ELs cannot be denied access to advanced and gifted and talented courses solely because of language barriers (ESSA, 2015;Lau v. Nichols, 1974), and it is insufficient to simply place ELs in these courses without language supports (Lau v. Nichols, 1974).

Implications for Policy
During the time of our study, 10 SEAs had EL populations at 10% or greater and historically homogeneous states continue to experience a rapid growth in the EL population (Sugarman & Geary, 2018). With these large numbers of ELs, are states ensuring that teacher specialists and mainstream teachers are prepared to teach ELs? If teacher credentialing is a proxy for quality, then our findings have implications for policies at the national, state, and local levels. Our findings suggest that teachers of ELs complete vastly different types of preparation and, by extension are likely have vastly different levels of pedagogical content knowledge and expertise for working with ELs. We argue that earning an ELD or bilingual education credential without coursework or mentored field experiences focused on ELs limits a teacher's ability to provide appropriate instruction, which violates ESSA (2015) and OCR (1970) mandates. Variability in teacher preparation would be reduced if the federal government required more explicit guidelines for the credentialing of all teachers to teach ELs (bilingual education, ELD, SEI, and mainstream). While SEAs should have the right to implement mandates as they deem appropriate for their populations, a minimal set of expectations related to rigor for teacher education should be set for all SEAs.
Compounding the problem of variation in teacher preparation is the fact that accountability for ELs has been decentralized to the states, making it impossible to explore correlations in teacher preparation and EL's outcomes. Clearly the centralization of accountability measures for academic and language growth, which would allow for comparisons across states.
To our best knowledge, SEAs do not differentiate between credentials resulting from the completion of an approved program (certification or endorsement) and those earned by less rigorous methods. As researchers and policy makers continue to seek understanding about how best to prepare teachers of ELs, they will need to tease out the qualifications of the ELD teachers within those states to explore possible correlations between the preparation of EL specialists and mainstream teachers and educational outcomes of ELs.
Although research shows the positive impacts of bilingual education on the educational outcomes of ELs (Collier & Thomas, 2017;Gándara & Escamilla, 2017), only 24 SEAs offer bilingual education credentialing. We view this as highly problematic and recommend that federal funding be authorized to incentivize the training and credentialing of more bilingual education teachers. This federal effort will capitalize on the bilingual abilities of ELs, which will increase the number of ELs who can become bilingual education teachers, and thus promote a growth cycle in the number of qualified bilingual education teachers.
Finally, given the teacher shortage particularly with regard to teachers of ELs (Cross, 2019), it would be beneficial to have credentialing information more readily available and easily navigable on SEA websites. For instance, New Hampshire's website explicitly named ELD as an area of critical shortage. While we could find information for a 'fast track' path for temporary licensure, we could not find information on how to earn the full standalone certificate or add-on endorsement. The inability to readily find credentialing information is important from a civil rights perspective: teachers (and administrators) need to know what their legal responsibilities are to ELs. Further, parents also have a right to know what education services their children are legally entitled to receive. Thus, we suggest that SEAs consider more streamlined ways to both publicize and catalog this information.

Implications for Research: Limitations and Future Directions
In our attempt to understand how SEAs are preparing teachers of ELs, we reviewed teacher credentialing requirements and professional teaching standards. Our work leads us to several implications for future research. First, our review of SEA credential requirements did not examine the specifics of state approved program requirements. Thus, it was not our intention to draw conclusions supporting an argument that completion of an approved program is indeed more robust than one, or a combination of, the following: coursework, practicum, subject matter test, language proficiency. We suggest that analyzing SEA requirements for their respective approved programs is another important area of inquiry with regard to the preparedness of teachers of ELs. Additionally, our analysis did not look at the differences between standalone licensure requirements and add-on endorsement requirements; arguably, add-on pathways that mandate 20 or more credit hours might be as comprehensive as a standalone program. Further, our current work was limited to traditional pathways to certification and endorsement and we did not examine alternative pathways such as district residency programs or Teach for America, both of which are widely popular routes to teaching as a profession (Darling-Hammond et al., 2005;Laczko-Kerr & Berliner, 2002).
Our review of SEA credential requirements did not examine specific coursework content for bilingual education and ELD specialists; future research examining coursework could be beneficial in understanding if this teacher preparation adequately meets the professional expertise required to teach ELs (e.g., see Brisk & Kaveh, 2019;Faltis et al., 2010;Valdés et al., 2013). Additionally, an analysis of coursework requirements across licensure pathways (e.g., standalone vs. add-on) would also be informative. Relatedly, an examination of practicum requirements for both specialists and mainstream teachers, including number of hours, type of mentorship or supervision, and setting are an important area of focus for future work. We limited our analysis of the professional teaching standards to binary reference to culturally and linguistically diverse students. Yet, our review of state professional teaching standards exposed wide variation in both language and the length of each document. Future research employing a full content analysis approach will be useful to the field.
Finally, it was not within the scope of this project to draw connections between teacher credentialing and SEA achievement data. Thus, we cannot currently suggest what might be the best preparation, or combination of experiences, for educators with regard to teaching ELs. Thus, future directions might also include examining the relationship between robustness of certification requirements and/or teaching professional standards expectations with state student outcome data; this of course, however, would require centralization of EL accountability measures.

Keywords
Examples of how keywords were referenced in standards Examples of keywords referenced in standards that were excluded culture The teacher uses understanding of individual differences and diverse cultures and communities to ensure inclusive learning environments that enable each learner to meet high standards.
Fosters a classroom culture where students give unsolicited praise or encouragement to their peers. culturally The teacher knows how to integrate culturally relevant content to build on learners' background knowledge. diverse Knows how to access information about the values and norms of diverse cultures and communities and how to incorporate students' experiences, cultures, and community resources into instruction.
Teachers demonstrate their knowledge of the history of diverse cultures and their role in shaping global issues.
Facilitates learners' ability to develop diverse social and cultural perspectives that expand their understanding of local and global issues and create novel approaches to solving problems. diversity Understands learning theory, human development, cultural diversity, and individual differences and how these impact on-going planning. English / English Learners identifying and using a variety of instructional strategies and resources that are appropriate to the individual and special needs of students, including students with disabilities, limited English proficient students, and gifted students Addressing the needs of ELs and students with special needs to provide equitable access to the content Language / language acquisition The teacher values diverse languages and dialects and seeks to integrate them into his/her instructional practice to engage students in learning.
Supports students in learning and using academic language accurately and meaningfully. Design instruction that accommodates individual differences (e.g., stage of development, learning style, English language acquisition, cultural background, learning disability) in approaches to learning. linguistic The teacher knows how to apply a range of developmentally, culturally, and linguistically appropriate instructional strategies to achieve learning goals. The teacher understands that each learner's cognitive, linguistic, social, emotional, and physical development influences learning and knows how to make instructional decisions that build on learners' strengths and needs.