The research's aim is to assess the services offered by Greek public secondary education schools, with the intention of identifying any discrepancies between students' expectations and their perceptions of the final services provided. The gaps discovered indicate that the school's educational services are not meeting student expectations in the five quality dimensions of the SERVQUAL model. To be specific, the average expectations are 4.44, perceptions are 3.11, and gaps are -1.33. The schools examined had a greater discrepancy in the dimensions measuring safety and emotional understanding, which was observed. The fact that the 5 factors are correlated with each other indicates the model's reliability. However, in relation to the independent variables of gender, age, and class, there appears to be a positive correlation across all factors, which is very weak and not statistically significant. In contrast, a low negative correlation appears to be present between only the demographics being considered. Therefore, demographic characteristics do not affect the quality of education in secondary schools. Our findings benefit decision-makers by assisting them in taking corrective actions necessary to enhance the quality of services provided by schools as part of a continuous improvement process in order to achieve a higher level of excellence. 

This study explores the implementation of Differentiated Instruction (DI) in Philippine multigrade classrooms and develops a tool to assess teacher proficiency in DI. Employing an exploratory sequential mixed-method design, the qualitative phase included focus group discussions with eight multigrade teachers, capturing their experiences and challenges in DI. These insights informed the creation of the Multigrade Differentiated Instruction Performance Appraisal Tool, which assesses DI proficiency across instructional planning, delivery, and classroom management. The tool underwent expert validation and reliability testing, with Cronbach’s Alpha of 0.91, indicating high internal consistency. The quantitative phase surveyed 163 multigrade teachers, revealing that DI implementation was generally effective, particularly in aligning lessons with curriculum standards (M = 4.09, SD = 0.73) and fostering a supportive learning environment. However, teachers faced challenges in utilizing technology, contextualized materials, and diverse assessment methods. Findings support the DI Assessment Checklist as a valuable tool for teachers and administrators to enhance instructional practices through reflective teaching. Recommendations include expanding training programs, improving access to instructional resources, and integrating DI-focused technology training. Further research should explore regional variations in DI implementation to inform more localized educational policies. This study provides practical insights to support teachers in effectively managing the complexities of multigrade education, ensuring equitable and inclusive learning experiences for diverse learners.