Student Evaluations of Instruction (SEIs) from about 6000 sections over four years representing over 100,000 students at the college of business at a large public university are analyzed, to study the impact of non-instructional factors on student ratings. Administrative factors like semester, time of day, location, and instructor attributes like gender and rank are studied. The combined impact of all the non-instructional factors studied is statistically significant. Our study has practical implications for administrators who use SEIs to evaluate faculty performance. SEI scores reflect some inherent biases due to non-instructional factors. Appropriate norming procedures can compensate for such biases, ensuring fair evaluations.