title: Health Science students' evaluation of courses and Instructors: the effect of response rate and class size interaction.
abstract: OBJECTIVE
  This study aims at investigating the effect of response rate and class size interaction on students' evaluation of instructors and the courses offered at heath science colleges in Saudi Arabia.
  
  
  METHODS
  A retrospective study design was adapted to ascertain Course Evaluation Surveys (CES) conducted at the health science colleges of the University of Dammam [UOD] in the academic year 2013-2014. Accordingly, the CES data which was downloaded from an exclusive online application 'UDQUEST' which includes 337 different courses and 15,264 surveys were utilized in this study. Two-way analysis of variance was utilized to test whether there is any significant interaction between the class size and the response rate on the students' evaluation of courses and instructors.
  
  
  RESULTS
  The study showed that high response rate is required for student evaluation of instructors at Health Science colleges when the class size is small whereas a medium response rate is required for students' evaluation of courses. On the other hand, when the class size is medium, a medium or high response rate is needed for students' evaluation of both instructors and courses.
  
  
  CONCLUSIONS
  The results of this study recommend that the administrators of the health science colleges to be aware of the interpretation of students' evaluations of courses and instructors. The study also suggests that the interaction between response rate and class size is a very important factor that needs to be taken into consideration while interpreting the findings of the students' evaluation of instructors and courses.
authors.affiliation: Assistant Professor and Supervisor General, Deanship of Quality and Academic Accreditation, University of Dammam.
authors.forename: Ahmed Al
authors.initials: AA
authors.lastname: Kuwaiti
keywords: Class size; Health Colleges; Response Rate; Student evaluation of teaching