Development of an instrument for measuring Spanish vocabulary knowledge

Fhis study addresses the need for a robust vocabulary assessment instrument to offer reliable estimates of vocabulary knowledge. Current measures often lack validation evidence and mainly serve instructional purposes. Therefore, this study presents the development of a valid, reliable assessment tool for research and evaluation. Adhering to Read and Chapelle's (2001) framework, we carefully selected context-specific resources to enhance the validity and reliability. Our results affirm the instrument's strong psychometric properties, demonstrating good validity (S-CVI/Ave: pre-test =.97; post-test =.98) and reliability (KR-20: pre-test =.883; post-test =.932). Moreover, the instrument displays sensitivity to various vocabulary instructional approaches [Kruskal-Wallis test, H (2) = 11.609, p =.003 from pre-test to post-test; H (2) = 12.434, p =.002 from pre-test to delayed post-test]. This study promotes vocabulary assessment literacy among language educators and researchers, ensuring the integrity of instrument development and enhancing language learning and research. By documenting the creation and validation of this assessment tool, our study contributes a valuable resource that enables educators and researchers to improve language education in accordance with contemporary measurement practices.