In favor of Vygotsky`s Socio-cultural theory and dynamic assessment (DA) investigations, the study sought to introduce a novel method to evaluate English-Persian translation proficiency level of translation trainees. Namely, the students` level of independent translation competence and their potentiality for learning were regarded as two factors contributing in the students` classification. Developing a computer-based translation placement test, and using interventionist approach of DA, the translation students participated in this study were categorized into three different levels, moving through two phases. Furthermore, considering the students` proficiency in every translation sub-competence defined in the test, students were narrowly reclassified. The results revealed the newly-made instrument is a valid and reliable scale for ‎evaluating translation trainees` actual as well as potential development. The analysis of the pilot test clearly demonstrated that besides assessing the students` current translation abilities, evaluating their learning potential has a profound impact on providing more thorough classification. The information yielded can be particularly beneficial in the translation students` future instructional planning.