Abstract
Considering the dependence of educational systems on books and materials, especially ESP textbooks that more closely linked with real context of use, the present study addresses methodological and epistemological shortcomings in this area through integrating sequential factor analysis with structural analysis in a balanced impacts matrix to develop a model of ESP textbooks inadequacies. To this end, some frequently used specialized textbooks in humanities were selected by purposive sampling. In addition to utilizing an expert panel for conducting semi-structured interviews, data were collected through systematic review and document analysis.Then, initial propositions were extracted using content analysis. Subsequently, a five-point Likert scale consisting of 25 items was subjected to Pearson correlation estimation for reliability assessment and confirmatory factor analysis for final validation. The results of the exploratory factor analysis showed that the construct of inadequacies in this area comprises 20 variables, which are categorized into four factors based on eigenvalue: theoretical, structural, procedural-process, and contextual. Furthermore, the results of the confirmatory factor analysis indicated that this construct has a good fit index in the Iranian context (Chi-square 1.02; Norm-based Fit Index 0.92; Comparative Fit Index 0.92; and Root Mean Square Error of Approximation 0.02). Structural analysis of the variables in the balanced scorecard matrix also showed that theoretical-methodological foundation, interactive needs assessment, and resource alignment are the main axes of the scenario for addressing shortcomings in this field. In addition to providing valid input for predictive research, these findings offer a suitable perspective for creating desirable changes for researchers and actors.

Introduction
English for Specific Purposes (ESP) textbooks constitute one of the most influential components of language education systems, particularly in higher education where instructional materials are expected to bridge disciplinary knowledge and communicative competence. Contemporary scholarship in language pedagogy consistently emphasizes that the effectiveness of language education programs depends substantially on the quality, structure, and contextual relevance of instructional materials. ESP textbooks occupy a particularly critical position because they are designed to prepare learners for specialized academic and professional contexts, thereby requiring close alignment with authentic communicative needs, disciplinary discourse, and contextual realities.
Despite the increasing theoretical sophistication in the field of language teaching materials development, many ESP textbooks used in Iranian universities continue to suffer from substantial methodological, structural, and contextual deficiencies. Previous studies have identified several recurring problems, including inadequate needs analysis, insufficient contextual adaptation, imbalance between linguistic and communicative dimensions, weak integration of learning theories, and limited attention to learner-centered instructional design. Furthermore, the majority of existing evaluation studies have adopted fragmented approaches that focus only on isolated dimensions of textbooks rather than providing a comprehensive and validated model of deficiencies.
The theoretical foundations of ESP materials development have evolved considerably over the past decades. Frameworks proposed by scholars such as Hutchinson and Waters, Jolly and Bolitho, Tomlinson, and McDonough have highlighted the importance of communicative language teaching, second language acquisition theories, sociocultural perspectives, cognitive approaches, interaction-based learning, and learner engagement in textbook development. These frameworks stress that effective instructional materials should not merely transmit linguistic forms but should also foster meaningful interaction, critical thinking, learner autonomy, contextualized communication, and affective engagement.
In the Iranian context, however, many ESP textbooks remain largely dependent on imported paradigms and generalized models that inadequately address local educational realities and learner needs. The absence of systematic evaluation procedures and context-sensitive frameworks has contributed to the persistence of epistemological and pedagogical shortcomings. Therefore, the present study sought to construct, validate, and structurally analyze a comprehensive model of ESP textbook deficiencies in Iranian higher education through a mixed-methods design integrating sequential factor analysis and structural analysis within a Balanced Impacts Matrix framework. The study aimed to answer three central questions: (1) What are the major factors and variables underlying deficiencies in Iranian ESP textbooks? (2) To what extent do these deficiencies correspond to the contextual realities of ESP instruction in Iran? and (3) What is the most compatible scenario for addressing these deficiencies within the Iranian educational context?

Research Methodology
The study adopted an innovative mixed-methods design grounded in sequential factor analysis and structural modeling. The research process consisted of three major phases: discovery of the preliminary model, validation of the model, and structural analysis of the identified variables.
In the first phase, data were collected through three complementary sources: systematic literature review, semi-structured interviews with an expert panel, and content analysis of selected ESP textbooks. The expert panel included nine university instructors specializing in English language teaching and ESP from several Iranian universities. Six frequently used ESP textbooks in humanities disciplines, including political science, theology, psychology, philosophy, management, and social sciences, were purposively selected for analysis. Through iterative coding and content analysis procedures, an initial set of 34 propositions related to ESP textbook deficiencies was extracted. After removing ambiguous, overlapping, and redundant items, a 21-item Likert-scale questionnaire was developed based on Dornyei and Taguchi’s guidelines for questionnaire construction.
The reliability of the preliminary instrument was assessed through a pilot study involving 26 ESP instructors. Cronbach’s alpha coefficients indicated acceptable internal consistency (α = 0.801). Subsequently, exploratory factor analysis (EFA) was conducted with data collected from 97 ESP instructors across Iranian universities. Statistical assumptions including sample adequacy, factorability, and multivariate normality were examined through KMO and Bartlett’s tests, both of which supported the suitability of the dataset for factor analysis.
The exploratory factor analysis, employing Varimax rotation, identified four major dimensions comprising 20 variables: theoretical deficiencies, structural deficiencies, procedural-process deficiencies, and contextual deficiencies. These factors explained more than 83% of the total variance. To validate the resulting construct, confirmatory factor analysis (CFA) was conducted using an independent sample of 119 ESP instructors. Goodness-of-fit indices demonstrated strong model validity (χ²/df = 1.02; NFI = 0.92; CFI = 0.92; RMSEA = 0.02). Finally, structural analysis was conducted using the Scenario Wizard software and Balanced Impacts Matrix in order to identify the most compatible strategic scenario for overcoming the identified deficiencies.

Discussion
1. Theoretical Deficiencies
The findings demonstrated that one of the most significant clusters of deficiencies in Iranian ESP textbooks concerns theoretical and epistemological foundations. These deficiencies include inadequate attention to teachability and processability principles, insufficient consideration of learners’ cognitive and affective readiness, neglect of learners’ prior knowledge and first-language influence, and limited integration of contemporary theories of second language acquisition and learning psychology.
The results suggest that many ESP textbooks still rely heavily on traditional transmission-oriented approaches that prioritize linguistic structures over communicative and cognitive engagement. This finding aligns with contemporary critiques of decontextualized language instruction and supports theories emphasizing meaningful input, interaction, scaffolding, and learner-centered instruction. Scholars such as Tomlinson and Snow have argued that language materials should facilitate emotional engagement, cognitive involvement, and meaningful communication rather than merely presenting isolated grammatical forms.
Another major issue identified in this category was the neglect of learner autonomy and higher-order thinking skills. The analyzed textbooks demonstrated limited support for reflective learning, critical thinking, exploratory learning, and metacognitive awareness. Such shortcomings weaken learners’ ability to internalize language knowledge and transfer it to authentic communicative situations. The absence of graduated scaffolding and insufficient attention to learners’ zones of proximal development further reduce the effectiveness of instructional activities.
2. Structural Deficiencies
Structural deficiencies constituted the second major dimension of inadequacies. These problems include weak linguistic coverage, imbalance between vocabulary density and grammatical load, inadequate integration of communicative competencies, poor visual design, limited formative assessment opportunities, and incompatibility with technological and multimedia learning environments.
The findings revealed that many textbooks fail to establish a balanced relationship between language structures and communicative performance. Although linguistic forms are frequently emphasized, learners are rarely provided with opportunities to develop authentic communicative competence within disciplinary contexts. This finding corresponds with communicative language teaching theories proposed by Canale and Swain, which stress that communicative competence extends beyond grammatical knowledge to include sociolinguistic, discourse, and strategic competencies.
Furthermore, the study demonstrated that the physical and visual design of textbooks often lacks pedagogical functionality. Insufficient use of visual elements, weak page organization, and lack of technological adaptability reduce learner engagement and fail to address contemporary educational expectations. In an era increasingly influenced by digital learning environments, textbooks that cannot integrate multimedia and interactive learning opportunities become progressively less effective.
The absence of systematic formative and summative assessment mechanisms was another important structural issue. Effective ESP materials should continuously monitor learner progress and provide opportunities for feedback, self-assessment, and reflective evaluation. However, the analyzed textbooks largely lacked such evaluative structures, thereby weakening instructional coherence and learner support.
3. Procedural and Process-Oriented Deficiencies
The third factor identified in the model concerns procedural and process-oriented deficiencies. These shortcomings include oversimplification of texts, excessive dependence on translation-based activities, neglect of semantic and pragmatic dimensions, insufficient feedback mechanisms, and weak sequencing of pedagogical tasks.
One of the most notable findings was the overemphasis on translation at the expense of communicative and interactional language use. The textbooks frequently treated ESP instruction as a process of lexical and grammatical decoding rather than as a means of meaningful disciplinary communication. As a result, learners were rarely encouraged to engage in authentic discourse practices or to develop pragmatic awareness.
Additionally, the findings revealed that many instructional activities ignored the pedagogical sequence of pre-task, task, and post-task stages emphasized in task-based language teaching frameworks. Effective ESP instruction requires cognitive preparation, meaningful task engagement, and opportunities for reflection and internalization. However, the analyzed textbooks often presented isolated exercises lacking pedagogical progression and interactional depth.
The absence of dynamic corrective feedback and interaction-based learning opportunities further weakened instructional quality. Most feedback mechanisms focused narrowly on grammatical accuracy rather than communicative effectiveness or learner development. This limitation contradicts contemporary views of language learning, which emphasize dialogic interaction, negotiation of meaning, and adaptive scaffolding as essential components of acquisition.
4. Contextual Deficiencies
Contextual deficiencies emerged as another central dimension of inadequacy. The study found that many ESP textbooks lack scientifically grounded needs analysis procedures and rely excessively on the personal experiences or assumptions of textbook authors rather than empirical educational needs.
Needs analysis is widely regarded as the cornerstone of ESP curriculum development because it determines the linguistic, disciplinary, occupational, and communicative requirements of learners. The absence of comprehensive needs analysis weakens the alignment between instructional materials and real-world language demands. The study demonstrated that insufficient attention to learners’ disciplinary goals, institutional contexts, and professional expectations contributes significantly to the mismatch between educational outcomes and actual communicative needs.
The findings also indicated that although some textbooks incorporate superficial cultural references, they generally fail to address deeper sociocultural dimensions of language use. Effective ESP materials should prepare learners to navigate cultural, institutional, and communicative complexities within specialized domains. However, the analyzed textbooks displayed limited sensitivity toward intercultural competence and contextualized discourse practices.
Finally, the structural analysis conducted through the Balanced Impacts Matrix identified three major strategic axes for improving ESP textbooks in Iran: theoretical-methodological foundation, interactive needs analysis, and resource alignment. These dimensions formed the most compatible scenario for overcoming existing deficiencies. The analysis emphasized the importance of professional development programs for textbook developers, collaborative needs analysis involving all stakeholders, and coordinated access to intellectual and structural resources required for effective textbook production.

Conclusion
The present study developed and validated a comprehensive model of deficiencies in Iranian ESP textbooks through the integration of sequential factor analysis and structural analysis. The findings revealed that deficiencies in ESP textbooks are multidimensional and encompass theoretical, structural, procedural, and contextual domains. The validated construct demonstrated strong reliability and validity indices, indicating its applicability within the Iranian higher education context.
The study showed that many existing ESP textbooks inadequately address contemporary theories of language learning, communicative competence, learner engagement, and contextual adaptation. Major shortcomings include weak needs analysis, insufficient integration of communicative and cognitive dimensions, overreliance on translation-based instruction, limited scaffolding and feedback mechanisms, and lack of alignment with technological and sociocultural realities. These deficiencies collectively reduce the effectiveness of ESP instruction and limit learners’ ability to develop meaningful communicative competence within specialized domains.
The structural analysis further demonstrated that sustainable improvement requires a multidimensional strategy centered on theoretical-methodological reform, collaborative needs analysis, and alignment of educational resources. Accordingly, curriculum developers, policymakers, textbook writers, and ESP instructors should adopt more context-sensitive, learner-centered, and theoretically informed approaches to materials development. The study contributes to the literature by offering a validated analytical framework capable of supporting future predictive and evaluative research while also providing practical guidance for improving ESP textbook development in Iran.