1 Introduction

Diagnostic testing helps students identify language proficiency deficiencies and strengths by providing personalized feedback. Unlike proficiency testing, it focuses more on targeted learning guidance. The effectiveness of diagnostic feedback depends on its communication with students and problem-solving strategies. Although diagnostic testing has received attention in the field of language testing, research on its application in teaching is still limited. Existing research focuses more on students' evaluation of diagnostic feedback and performance improvement, but lacks in-depth exploration of the process of using diagnostic feedback by students in specific environments. This study adopts case study and follow-up experimental methods to investigate in depth how students evaluate and use diagnostic feedback in college English classrooms, as well as the impact of diagnostic feedback on learning. The aim is to provide ideas and suggestions for the effective application and high-quality model construction of diagnostic feedback.

2 Research Design

This chapter introduces a study on the application of English reading diagnosis feedback for non English major sophomore students in a domestic university. The research subjects were 12 students who participated in diagnostic tests and were interviewed and recorded in reflective journals. The research tools include the Youjixue online English proficiency diagnosis system, semi-structured interviews, and reflection logs. The diagnostic test covers 6 reading micro skills, and the generated report includes overall performance, sub item performance, diagnostic trajectory, typical questions, and recommendations. The interviews were conducted at the beginning and end of the semester to understand students' views on diagnostic feedback and the effectiveness of remedial actions. The reflection log records the process and feelings of students using diagnostic feedback. The data collection includes face-to-face interviews, reflection logs, and second round interviews, analyzed using a dual cycle coding method, and ultimately formed four categories, each containing two to four codes. During the research process, the analysis memo is used to record coding choices to improve the certainty and credibility of the research results.

3 Results and Discussion

Students generally have a positive evaluation of the diagnostic feedback, believing that the report design is clear and easy to understand, and the charts are intuitive and effective. However, some students think that the report is too long and suggest that some parts be lengthy. Students expect to receive feedback at the topic level and more explanations about micro skills. The correlation between diagnostic feedback and academic English reading and writing courses has been recognized, but there is a lack of consideration for the special language style of academic English. Students believe that diagnostic feedback is helpful in improving their English proficiency, especially in the performance section. However, there are mixed evaluations of Dr. U's suggestions, with some students considering them too broad.

4 Conclusion

This study investigates the application of diagnostic feedback from Youjixue reading in college English classrooms from the perspective of students. Students hold a positive attitude towards diagnostic feedback and have a positive impact on their learning through self-directed learning activities. The study extracted the characteristics of effective diagnostic feedback and proposed five suggestions: 1) Diagnostic feedback should be in line with the course content and learning objectives; 2) The feedback form should be concise in language, clear in structure, and can use charts to visually present information; 3) The feedback content should include overall exam performance, micro skill strengths and weaknesses, micro skill concepts, the correspondence between questions and micro skills, and specific and practical remedial behavior suggestions; 4) Provide personalized learning resources; 5) Teachers should regularly organize diagnoses to track students' progress. These features have implications for the field of diagnostic feedback and can provide recommendations for developing, evaluating, and improving diagnostic feedback. The study emphasizes that students are decision-makers and actors in learning oriented diagnostic tests. Based on their understanding and evaluation of diagnostic feedback, they decide whether and how to use it, which affects the effectiveness of the test. The study provides new ideas for the application of diagnostic feedback in college English teaching, but the results are influenced by the subjects and environment. Future research can continue to explore the use in different subject groups and teaching environments, and adopt multiple research methods for cross validation.