Successful teachers always think of using new teaching techniques which produce positive changes in students' reactions. Williams and Burden (2000) argue that teachers enhance their students' confidence, motivate them, improve their self-esteem and organize a proper learning atmosphere. These teaching may be directed from different teacher internal as well as teacher external sources: teacher knowledge, skills, teacher personality, and teacher professional development programs. In order to be influential teachers, teachers require possessing different professional developmentskills along with the knowledge of their subject matter and teaching experiences.

Having reviewed previous research on teacher professional development, Desimone (2009) focused the components of meaningful and impactful teacher professional development which finally result in enhancement in students’ performance. These five critical components are (1) the need for focus on content; (2) the opportunities presented for active learning; (3) coherence of the professional development program; (4) duration (minimum of 30 hours) of the program; and (5) opportunities for collective participation. In addition to these five critical factors, research document also states to the requirement to integrate structured, maintained activities to improve the benefit of any professional development program. Improvement and change in teachers’ knowledge and practice are likely to bring about changes in teacher growth, verities in teachers’ instructional techniques and strategies as well as enhancement in student learning. Review of the related literature on teacher professional development programs represents that different inquiry-based models to professional development (e.g., Critical Friends Groups, Bambino, 2002; Peer Coaching, Ackland, 2000; Lesson Study, Takemura & Shimizu, 1993; Cooperative Development, Edge, 1992; and Teacher Study Groups, Burns, 1999; Clair, 1998; Dubetz, 2005) have been designed to make a mediational context for teachers to use in continuous, systematic, and reflective examination of their pedagogical activities and their students' learning (Johnson, 2009). The following sections provide a background to the concept of teacher professional development, reviews the prior related studies, and explains the details of the development and validation of the English language teacher professional development inventory in the current paper.

LITERATURE REVIEW

Teacher Professional Development

According to Stes, Min-Leliveld, Gijbels and Van Petegem (2010), teacher professional development is a term including a lot of teacher education programs, plans or experiences which may adjust from workshops to critical reflection on teachers’ teaching profession either by one teacher or by a team of colleague teachers, to classroom observation of a teacher, to hallway conversations among teachers and teacher directors. Teacher professional development has called by such names as ‘academic development’, ‘educational development’, ‘faculty development’, and ‘instructional development’.

Research represents (e.g. Wei, Darling-Hammond, Andree, Richardson, & Orphanos, 2009; Wenglinsky, 2002; Wilson & Berne, 1999) that teacher professional development is a foundation of educational improvements which explores to enhance student achievement. Lawless and Pellegrino (2007) discuss that teacher professional development plays a vital role in developing teachers' instructional actions in the content areas, knowledge of standards-based evaluation, use of new instruments and strategies. Likewise, professional development of teachers could cause positive shifts in teachers and can play a main role in improving instructional techniques as well as enhancements in student learning. Avalos (2011) notices that teacher professional development is about teachers’ learning, learning how to learn, and transforming their knowledge into practice for the benefit of their students' growth.

Research (Corcoran, 1995; Corcoran, Shields & Zuker, 1998; Fullan, 2001; Guskey, 2002; Lieberman & Pointer Mace, 2008) has investigated professional development of teachers as a device which governments and organizations have utilized to introduce a variation. It is to be considered that these devices should be a maintained and carried on process given they are effective in enhancing schools, increasing teacher quality, and boosting student achievement (Day, 1999; Hargreaves, 2000; Opfer & Pedder, 2011; Verloop, 2003). Hoyle and John (1995) identify teachers' professional development in their book named "Professional Knowledge and Professional Practice," as "the process by which teachers obtain the knowledge, skills and values which will enhance the service they provide to them" (Hoyle & John, 1995, p. 17). Vonk (1991) debates that teacher professional development is the process of acquiring skills, professional knowledge, values and personal qualities that provides teachers to reconcile within the educational system. According to Kelchtermans (2004), teacher professional development is “a learning process which shows a meaningful interplay with the context (both in time and space) and finally directing to alterations in teachers' professional action and their thinking about that action” (p. 220). Such activities which augment teacher knowledge and skill and contain reflective activities and collaboration (Schraw, 1998; Timperley, Wilson, Barrar, & Fung, 2007; Verloop, 2003) are examined to be necessary for teacher professional development. Increase of research (Desimone, 2009; O'Hara, Pritchard, Huang, & Pella, 2013) has pointed out the effect of some factors including a content area focus, for hands-on and active learning, relationship with previous professional experiences, collective participation with colleagues, and important contact hours in a continuous meetings, collaboration, and Reflection (DuFour, DuFour, & Eaker, 2008), technology connection (Hughes, Kerr, & Ooms, 2005; Keller, Bonk, & Hew, 2005; Lawless & Pellegrino, 2007; Mouza, 2009; O'Hara, Pritchard, Huang, & Pella, 2013; Walker, Recker, Ye, Robershaw, Sellers, & Leary, 2012). Darling-Hammond and Sykes (1999) mention that personal development is a shared, public process; increases maintained communication; emphasizes real school-related concerns; depends on internal skill; expects teachers to be active participants; emphasizes on the why as well as the how of teaching; brings about a theoretical research base; and expects that alteration will be a slow process in the new pattern.

      In the related literature, different endeavors have been made to better understand teacher professional development (e.g., Freeman, 2001; Freeman & Johnson, 1998; Richards & Farrell, 2005; Ur, 1996) as well as study the impact of teacher professional development programs on alterations of teachers and on students' achievements (Ashton & Webb, 1986; Avolas, 2011; Harris & Sass, 2007; Lovett, Lacerenza, de Palma, Benson, Jacob, & Lefgren, 2004; Vogt & Rogalla, 2009), increasing student motivation (Ermeling, 2010; Frey & Fisher, 2009; Guay, Valois, Falardeau & Lessard, 2016; Levine & Marcus, 2010; Morais, Neves, & Alfonso, 2005; Seymour & Osana, 2003), improving technical knowledge (Ponte, Ax, Beijaard, & Wubbels, 2004), teachers' attitudes and actions based on student self-regulated learning (Hoekstra, Brekelmans, Beijaard, & Korthagen, 2009), teacher satisfaction and enhancement of curricular understanding and developed self-efficacy (Lovett et al., 2008; Nielsen, Barry, & Staab, 2008; Nir & Bogler, 2008). Garet, Desimone, Birman, and Yoon (2001) have argued vital features of professional development activities that have significant, positive effects on teachers’ self-reported increases in knowledge and skills and changes in classroom action: (a) focus on content knowledge; (b) opportunities for active learning; and (c) communication with other learning activities.

There are also studies which have examined the effect of principles on teacher professional development. For instance, Clement and Vandenberghe (2001) and Moore (2000) came to a result that educational supervision, as a cooperative problem solving process, plays a significant role in English language teachers’ professional development. Andrews (2007), Borg (2001), Farrell and Lim (2005), Nishimuro and Borg, (2013) and Underwood (2012) represented that teachers’ real knowledge in different fields of language which affects on their teaching, their prior beliefs, attitudes and thoughts are vital in their professional development. Elliott (2010), Grossman, Wineburg, and Woolworth (2001), Meirink, Meijer, and Verloop (2007), and Vescio, Ross, and Adams, (2008) pointed out that teacher collaboration helps teachers to foster their teaching skills and maintain their professional development.

Prior research (e.g. Bakker & Bal, 2010; Barth, 2006; Dillon, 2003; Geijsel, Sleegers, Stoel, & Krüger, 2009; Goddard & Tschannen-Moran, 2007; Retallick & Butt, 2004; Vescio, Ross, & Adams, 2008) has displayed the impact of teacher autonomy and collegial advocate on teachers' learning and development. In other words, collaborative actions and collegial associations organize significant working conditions for teachers and as such they affect the professional development of teachers and school. By taking this organizational and contextualized approach, we relate most writers on the concern (see e.g. Hargreaves 2000; Southworth 2000). Cormany, Maynor, and Kalnin (2005), Mcdonough (2006). Smith (2005) believed that approaches to teacher education emphasize teacher reflection in teachers’ professional development. Ottesen (2007) and Tinning (2006) proposed reflective teacher education as an appropriate approach for utilize in teacher education programmes. The complex disposition of teaching and learning requirements of teachers is to become reflective and be able to adjust to different classroom situations (Moe, 2013; Ottesen, 2007; Tinning, 2006). Moreover, Chen (2012) and Reinders (2009) have displayed the integration of educational technology in teacher professional models (e.g., a concerns-based model). Most professional development related to digital instruments and new literacy are short-term, workshop-based, and organized with technologies (Coiro, 2005; Curwood, 2011; Mouza, 2009; O'Hara, Pritchard, Huang, & Pella, 2013; Walker et al., 2012).

Furthermore, the significance of teachers’ professional development (TPD) is identified by Iranian researchers and in the current years, there have been some activities and programs for teachers' development. Therefore, there are not enough documents on systematic designing and administration of the teacher professional programs for the teachers. The outcomes from the selected programmes have displayed that teachers’ professional development (TPD) were not successful to achieve the predetermined goals (Rogan, 2004; Tecle, 2006). Based on Consortium of Institutions for Development and Research in Education in Europe (2010), professional development activities were found to be ineffective in many perspectives due to the decreasing number of teachers to participate. Most of in-service trainings were not influential in achieving the pre-determined aims. The most significant reason for this breakdown is that the training doesn’t have the components of self-understanding which is necessary for self- development and enhancement (Consortium of Institutions for Development and Research in Education in Europe, 2010). The reasons for disregarding some teachers' professional development (TPD) practices have become the subject of many discussions (Gordon, 2008; British Council, 2003; Tahemi, 2004; Department of Education & Employment, 2000). There have been worthwhile attempts in Iranian education system towards training and improvement; therefore, in the current situation, the educational system of the country requires new prospects towards the improvement and professional promulgation of the primary teachers. This could be carried out only through independent research about the assessment of teachers' professional development (TPD) in Iran.

According to Ghoshooni (1995), different human and financial resources have been allocated for administrating teacher training sequentially. Therefore, it is a need that all resources should be used efficiently to achieve the standard professional development goals of teachers in education. Problems and drawbacks in the programmes of the teacher’s professional development (TPD) are amongst the concerns that have been conveyed less attention and investigation. Therefore, Bolam (1998) in his study stated that continuous evaluation of in-service training courses is too important. Without assessment, it would be impossible to meet the requirements of the teachers.

In spite of the aforementioned studies on the effectiveness of teacher professional development on teacher and student success to the best of our knowledge, no instrument has been reported for measuring the English language teacher professional development. This study is unique in the way that TPD is conceptualized in this study as a construct with three components. This paper does not aim at describing these models. Rather, it intends to unravel components which are likely to influence English language teachers’ professional development. Based on the previous research and theory on teacher professional development, three components of knowledge of English language teachers, skills and TPD programs in which English language teachers may take part have been identified to be as the main components of a teacher professional development model. According to Johnson (2009), once we define what English language teachers need to know (i.e. teachers’ knowledge) and are able to do (teachers’ essential teaching skills), or types of experiences (teacher education programs), we come to know what it means to be an English language professional teacher.

PURPOSE OF THE STUDY

The construct of teacher professional development may have been well elaborated on in the related literature. However, we still do not have a thorough picture about what teacher professional development could entail and what components it consists of mainly due to the dearth of instruments for measuring teacher professional development. Hence, the purpose of this study is two-folds: one is to give a rather inclusive state of the art studies on TPD, related scales and inventories and two is to justify, define, develop and validate a teacher professional development scale in an EFL context. It intends to fill this gap by first proposing a model of teacher professional development and second developing and validating an instrument to allow for the quantification of the construct. Building on data gathered from Iranian EFL teachers, it, then, conducts its empirical investigation in an Iranian EFL context through exploratory and confirmatory analyses. With the instrument developed and validated in the current research. we, in fact, make the first attempt to examine What EFL teachers’ professional development consists of and whether the scale developed accordingly is valid or not. Specifically, the research question answered in this study was:

What does an ELT professional development scale consist of and whether the developed scale demonstrates an appropriate level of reliability and validity or not?

In the following, details of the development and validation of an English Language teacher professional development inventory are explained.

METHOD

Participants

A total of 450 experienced and novice male and female teachers at different state, rural and urban schools, language institutes, and centers of higher education studying English took part in the study from 3 provinces including Tehran, Ilam and Mazandaran. Their gender was not taken into consideration. Their ages ranged from 23 to 49 years. They are in different degrees including bachelor of art, master of art and Ph.D. Their teaching experience varies from 2 years to more than 15 years.

Data Collection Procedure

We went through two steps in the current paper. First, we developed a teacher professional development inventory and second we validated it based on the collected data from a number of Iranian EFL teachers. Below we explain the instrument development and validation in detail.

 Instrument Development of a Proposed Model of Teacher Professional Development  

The first step in developing the TPD instrument involved a comprehensive review of the related literature pertinent to teacher professional development. It allowed us to check for any existing model as well as instruments that might already have been used for assessing related constructs and behaviors in teacher professional development while drawing on the standard procedure for developing a valid and reliable measurement instrument (Brown, 2001 and Dornyei, 2003). The prior related literature provided us with an initial draft of the constructs and concepts which were considered to be pertinent to teacher professional development. This review resulted in defining the construct and collection of more than 300 items out of which a temporary data driven model of teacher professional development was developed. To develop such a model, the researcher went through a cycle of construct definition, item accumulation, item arrangement, model development, and model test. In the next stage, those items that overlapped or were mere repetitions of one another were deleted and the list was reduced to 130 items.  

To evaluate content validity, we asked three field-specific experts with expertise in TPD to consider the initial pool of 130 items and to rate the extent to which each item measured what it claimed to measure in the three components of knowledge, skills and programs, using a 5-point scale (with 1 being to the least extent and 5 being to the greatest extent). Moreover, we asked the experts to give their suggestions and comments for each item with lists of possible items for each subcomponent.

The researchers then collaborated with the three field-specific experts to review the ratings and suggestions, and made revisions to several items. For example, the content-validity experts suggested we combine the components of skills and personality traits into one component due to overlaps in many areas. Also, they recommended that we avoid using items that contain a negative construction (i.e., including “not,” “doesn’t,” or “don’t”).

Additionally, the experts suggested we revise some items by adding some related concepts to them. Finally, we worked closely with two of the experts to rewrite items for all knowledge subscales. The final stage involved going over all the developed items and checking them all once again to ensure that they measured what they claimed to measure. This stage in the analysis resulted in the three components of teacher professional development including knowledge, skill and programs and their related subcomponents, to be measured and validated in the subsequent phases of the study.

Moreover, interviews were conducted with 12 experts in the fields of applied linguistics, university professors as well as PhD teacher students who were familiar with teacher professional development and its theoretical underpinnings. The interviews lasted from 20 to 45 minutes in length. They were all tape-recorded and later transcribed for final content analysis. Efforts were made to elicit responses from the interviewees to questions concerned with the nature of teacher professional development, its components and sub-components which can be subsumed as its constituent elements. In this phase of the study we sought to find out whether any alternative model of teacher professional development can be developed, and whether our initial components and sub-components matched the ones that the experts suggested we add to or remove from the model.

In the next step, 7 of the interview participants were invited to have another analytic look at the instrument. The purpose of this phase was to have a second professional opinion on the component make-up of the model and to make use of ‘experts’ judgment’ for item redundancy, clarity and readability, the three principles were advocated by Dornyei (2003). This expert analysis of the instrument was resulted in a further truncated model. Additionally, based on the experts’ opinion on the items’ clarity and readability, some items were revised in the wordings. Based on the frequency with which each item was selected as relevant by the 7 experts, 130 items were selected for inclusion in the instrument. Next, a 5-point Likert scale ranging from ‘‘very much’’ to ‘‘not at all’’ was chosen to assess English language teachers’ professional development while taking into account the standard outlines for the questionnaire development advocated by Brown (2001) and Dornyei (2003). The 130-item questionnaire was given to two applied linguistics teachers with language teacher education background for proofreading and face validity assessment, resulting in some minor alterations in the wording of a few items. The instrument was then piloted on a group of 400 ELT teachers.

Instrument Validation

To validate the instrument, we sent it out to 450 practicing English teachers at different state rural and urban schools, language institutes, and centers of higher education in Tehran, Ilam and Mazandaran provinces of Iran. We received 435 from among the received instruments. 400 questionnaires were considered for analysis as the rest were either incomplete or carelessly completed. 257 were males (64.25%) and 143 were females (35.75%). The respondents had varying years of experience ranging from 5 (11%), 7 (14%), 11, (30%), 17 (27%) to 25 (18%) years.Methods used for instrument distribution were both face to face contact and email correspondences.

Table 1: The tentative model, its components and sample items

Data Analysis Framework

Among the current frameworks for model validation and assessment, Mulaik and Millsap (2000) suggested Exploratory Factor Analysis (EFA) and Confirmatory Factor Analysis (CFA). Our instrument validation process was performed in two Macro-Phases: Exploratory Data Analysis (EDA) and Confirmatory Data Analysis (CDA) with each of which were including a number of reliable evidence of micro procedures. Below we provide a brief descriptive account of our data analysis framework of the study.

RESULTS

Exploratory Factor Analysis

In this research, at first, EFA (Exploratory Factor Analysis) based on principal component approach with Varimax rotation was performed on 130 items. Items loaded heavily on more than one factor, and items that did not load heavily on primary factor were deleted and removed from further analysis. Only factor loadings above 0.4 are shown in Table 3 (Raubenheimer, 2004). Factors with eigenvalues greater than 1 were retained, which is a rule used in judging the adequacy of the factor solution (Lysonski et al., 1996). This level resulted in the removal of 28 items in our sample loaded, resulting in 3 factors. The three factor solution explained 69.368 percent of the total variance. The results in Table 2 showed that the data with KMO = .981 (> .7) and Bartlett's Test of Sphericity (chi-square = 45400.695, df = 5151, p = .000) were factorable.

Confirmatory Factor Analysis

The confirmatory factor analysis (CFA) was utilized to check and investigate the number of explored factors. The maximum likelihood algorithm of LISREL 8.8 version was used for the calculation. Figure 1 shows that all the standardized loading factors were above the cut-point of 0.5 stated by Hair et al, (2006) and t-values for all the standardized factor loadings of the items were discovered to be significant (p > 0.05). Also, the fit indices (CFI, NNFI, RFI, SRMR and RMSEA) for the single factor structures were also above the plausible levels for all factors (Table 4). The minimum cut-off value for model validation is

Figure 1: Fitted CFA model

In addition, to assess the convergent validity of constructs at the latent variable level, the index of Average variance extracted (Fornell & Larcker, 1981; threshold value = 0.5) was performed. Moreover; further results indicated that the AVE values were above the recommended level of 0.05. Thus, all latent variables in the model were statistically valid.

Table 4: Absolute and incremental fit indices for CFA model

DISCUSSION

The current paper explained the development and validation of an instrument for measuring teachers’ professional development in English language pedagogy. To this end, we created a model including exploratory and confirmatory analyses. This model was, in fact, used to examine the construct validity of a proposed three-factor model, i.e. knowledge, skill and TPD programs. As stated upon earlier, the hypothetical model was developed based on a comprehensive review of the literature related to teacher professional development and was then examined on a sample of 400 EFL teachers while using EFA, CFA and Model Evaluation estimates. Although all the three initially proposed components in the instrument were substantiated by the collected data, 28 of the items did not statistically load during exploratory data analysis phase reducing the inventory to 102 items. All of the remaining 102 items tapping into knowledge, skill, and TPD programs were found to have significant statistical relationships with their matching factors (see Appendix A for the final version of the instrument). The calculated model-fit approximations also confirmed this CFA model as a reliable assessment of teacher professional development. More specifically, item 4 did not load on content knowledge, items 11 and 12 on technology knowledge, item 28 on technological, pedagogical, and content knowledge, item 36 on planning and preparation (of the skill component), items  40, 42, 44 on lesson presentation (of the skill component), items  47, 48,  and 52 on lesson management (of the skill component), 58 and 61 on classroom climate control (of the skill component), items 65 and 69 on assessing students’ progress (of the skill component), items 75 and 76 on reflection and self-evaluation (of the skill component), items 87, 89, 93 and 94 on supportive emotional skills (of the skill component), items 102 and 103 on the content of teacher professional development (of the TPD programs), items 108 and 112 on Pedagogies of TPD programs (of TPD programs) and items 122, 123 and 124 on the institutional forms of delivery in TPD programs (of TPD programs).

Although further research is required to examine why these 28 items were dropped out in the exploratory analyses, some of them can be justified with reference to the context of the study. For instance, the removal of items 11, 12, and 28 was caused as a result of the participants’ unfamiliarity or little familiarity with technology which is a common problem among Iranian EFL teachers. Items relating to teachers’ necessary teaching skills which did not survive in the exploratory phase of the data analysis was likely caused as a result of little ability (or no ability) of Iranian EFL teachers in planning, preparing, presenting, managing their lessons, controlling classroom climate, evaluating students’ progress, reflecting on their and self-evaluating teaching practices and providing emotional advocate to their students. Finally, the omission of items evaluating the content, pedagogies and the institutional delivery of the teacher professional development in the exploratory phase can be linked to the poor quality of these programs which need to be enhanced in every perspective of what establishes a successful teacher professional development programs.

All in all, the present research moves forward our theoretical and practical understanding of teacher professional development in at least three important ways. First, previous theorizing on this subject had emphasized primarily on examining factors affecting as well as being affected by teacher professional development while placing less emphasis on other equally important aspect of teacher professional development, i.e., development and validating a relevant inventory. Second, the current inventory was developed to afford evaluation of multi-competences involved in teacher professional development specifically emphasizing on the degree to which teachers are professionally developed. Third, the teacher professional development originated out of a strong theoretical and experimental tradition and dated the translation of this notion into practice including the development, validation and testing of teacher professional training or interventions has been almost lacking.

CONCLUSION AND IMPLICATIONS

The absence of an instrument to measure teacher professional development prompted the current study. To this end, the present paper drew on prior research and theory, developed and validated a novel instrument – a Teacher Professional Development Inventory (TPDI) – which measures the extent to which EFL teachers are professionally developed and make teachers aware of multiple competences which constitute professionally developed teachers. These competencies are, in fact, essential components of teacher professional development that a teacher is expected to possess and be able to translate into everyday teaching and learning practices in the classroom settings which, in turn, leads to achievement of the students. Lawless and Pellegrino (2007) argues that once professional development is improved, it helps teachers develop their instructional practices in the content areas, knowledge of standards-based assessment, and innovative use of new tools and strategies. Moreover, professional learning is a process rather than a product, takes time and space. It also involves commitment and patience. We argue that effective professional teacher development still remains, according to Borko (2004, p.3), “woefully inadequate” which calls for a need to look to outside variables impacting on teacher professional development to respond to teachers immediate dynamic and their professional growth needs.

As to the implication of this study, the inventory developed and validated in this study can hopefully be considered a valuable tool for measuring the extent of English language teachers’ professional development in similar pedagogical EFL contexts. For example, it allows officials involved in language teaching and learning curriculum development to assess the degree of their English teachers’ professional development and design and implement both pre-service and in-service teacher professional development schemes for them, accordingly. Moreover, private language teaching and learning institutes can, to a greater extent, contribute to enhancement of English language instruction by employing professional developed English language teachers. They can usefully employ the TPD inventory developed and validated to examine English language teacher applicants’ extent of teacher professional development and hire those teachers who are highly or relatively highly professionally developed. 

And a final caveat is that due to the particularities of every EFL teaching context, the applicability of the TPD inventory developed and validated in the present study in other pedagogical contexts may remain unclear. Therefore, further replication studies are needed to better operationalize teacher professional development and make necessary modifications to model’s factor structure. Despite this, the researchers believe that the inventory which was developed and validated in this study can be considered to be a valuable tool for researchers and can measure their extent of their professional development in similar pedagogical EFL context.