Construction Validity Testing on Blended Learning Implementation Evaluation InstrumentsMuhammad Yusuf, Andi Andariana, Perawati Bte Abustang, Abdul Mannan, Muhammad Ansarullah S. Tabbu, Dinil Qaiyimah and HarisE3S Web Conf., 400 (2023) 01007DOI: https://doi.org/10.1051/e3sconf/202340001007