Dynamic assessment is a method of evaluation that facilitates and diagnoses students' developmental potential by providing mediated support during the assessment process. Compared to traditional assessment methods

dynamic assessment can more effectively analyze learners' capabilities and more accurately predict their future development. This study explores the application of dynamic assessment in English speaking instruction and its impact on learners' self-efficacy. Self-efficacy is a core concept in social learning theory and is considered a significant factor affecting learners' language proficiency. The results indicate that experimental teaching with dynamic assessment is an effective way to foster learners' self-efficacy

but its effectiveness varies among learners with different levels of efficacy. This suggests that in future practice

when applying dynamic assessment teaching

evaluators should update their intervention guidance in real-time according to the changes in the zone of proximal development of learners at different levels

to promote the development of all learners. Self-efficacy is an important indicator for validating the effectiveness of dynamic assessment and has a significant impact on the effectiveness of dynamic assessment experimental teaching.