1 Introduction

The research background of English for Specific Purposes (ESP) was introduced, emphasizing the importance and disciplinary specialization of ESP proficiency testing. Early research focused on teaching and practice, but with the development of teaching, scholars began to pay attention to ESP ability testing. Unlike regular English proficiency tests, ESP proficiency tests aim to measure learners' mastery of specific subject areas or professional English. At present, research results mainly focus on the design principles, backlash effects, and testing effects of large-scale ESP tests, and there is still insufficient research on ESP ability scales. This study aims to review the current research status, difficulties, solutions, and future prospects of ESP proficiency scales both domestically and internationally, providing reference for the development of ESP testing in China.

The Development Trend of ESP Ability Scale Research

Explored the development trend of ESP ability scale research in the past thirty years. Since 1994, the academic community has been paying attention to ESP testing research. Through searching in CNKI and Web of Science databases, a total of 512 relevant literature were collected, of which 40 were related to scale research, accounting for 7.8%. Before 2005, the attention to ESP testing was not high. After 2006, the number of publications increased year by year, but decreased slightly in 2020. The research on ESP ability scale started relatively late, with the first literature published in 1999. It gradually gained attention after 2012, but the proportion of publications is not high, and further exploration is still needed in this field.

A Review of the Research on ESP Ability Scale

The research on the domestic Business English Proficiency Scale has gradually developed since the introduction of the Cambridge Business English Certificate Examination in China in 1993. After the Ministry of Education approved the establishment of the Business English undergraduate major in 2007, the academic community began to pay attention to the research on Business English testing. Early research mainly focused on scale design, such as the Business English Writing Ability Scale designed by Fang Ming (2010), but there was insufficient testing of reliability and validity. After the implementation of the National Standards for the Quality of Undergraduate Teaching in Business English Majors in Higher Education Institutions, research on the Business English Proficiency Scale has received more attention. For example, Wang Lifei et al. (2015) analyzed the reliability and validity of the National Business English Proficiency Test Band 4, and Wang Cong and Yang Yan (2016) elaborated on the development ideas of the Business English Oral Proficiency Scale based on the theory of communicative language competence. The research on foreign business English proficiency scales has stronger purposefulness and practicality, and is worth referring to domestically. After the release of the China English Proficiency Scale (CSE), the domestic academic community began to explore its impact on ESP assessment research. CSE provides theoretical basis and descriptive language reference for the design of ESP proficiency scales, expanding the subject of ESP assessment. In addition to Business English, domestic scholars have also explored the design of ESP scales in other fields, such as the "Listen Read Write" test scale designed by Jia Wenfeng and Zhang Peixin (2018). The research on ESP proficiency scales abroad focuses more on the validation of scale validity, emphasizing that exam standards should be combined with the requirements of language practical application scenarios. For example, Brown (1995) explored the influence of rater background on scoring results, and Jacoby&McNamara (1999) analyzed the differences between the scoring rules of vocational English tests and the requirements of actual work scenarios. Foreign research also involves the construction of overall ESP assessment standards and the design of communicative language proficiency models. Overall, scholars at home and abroad have different research focuses on the ESP ability scale. In China, the main approach is to construct theoretical frameworks, while in foreign countries, empirical research on validity is more common.

Difficulties and Solutions in the Research of ESP Scale

Discussed the difficulties and solutions in the research of ESP scale. The difficulties include the complexity of constructing a descriptive language bank and verifying its validity. The establishment and classification of a descriptive language bank are key and complex steps, while the validity testing step is equally complex. In terms of solution ideas, methods such as emphasizing the establishment of descriptive language databases, referencing existing scale rules, integrating disciplinary knowledge requirements, and inviting experts to participate in grading and verification have been proposed. At the same time, the importance of comprehensively and systematically testing the validity of scales from different validity perspectives was emphasized, and it was suggested to strengthen collaboration among interdisciplinary researchers.

5 Prospects for Future ESP Capability Scale Research in China

The importance of the ESP proficiency scale in foreign language assessment was emphasized, and two key directions for future research were pointed out. Firstly, it is necessary to strengthen the research on interdisciplinary ESP competency scales, especially in areas other than Business English, to meet the demand for internationally competitive talents. Secondly, the ESP proficiency scale should reflect a shift towards content language integration, combining subject knowledge content with language proficiency assessment to meet professional requirements. When designing an ESP scale, both linguistic and professional aspects should be considered to ensure that the scale can measure both language proficiency and assess language use ability in specific contexts.

6 Conclusion

The development of ESP research in China has achieved fruitful results over the past 30 years, but with the increasing demand for interdisciplinary fields and the cultivation of composite talents, it still faces many problems. ESP testing is the key to teaching, and the ability scale is the breakthrough point. The scientific assessment system contributes to the comprehensive construction of the ESP curriculum system. This study reviews the research on ESP ability scales in the past 30 years both domestically and internationally, looks forward to its development direction, and anticipates more achievements.