Section 8.5 Confounding Variables

Section 8.5 Confounding Variables

Section 8.5 Confounding Variables


Confounding variables refer to anything that may impact on the ratings or feedback provided by students, other than those being overtly evaluated. Some researchers have suggested that students are competent in their feedback and give higher ratings to instructors from whom they learn most and are, in general, not overly influenced by extraneous characteristics (Beran & Rokosh, 2009).


However literature is replete with examples of unanticipated factors impacting on SET and threatening the reliability and validity of the process (Balam, & Shannon, 2010; Germain and Scandura 2005; Sproule, 2002) and reducing it to a meaningless quantification of personality contests (Spooren, Mortelmans, & Denekens, 2007). Forty issues identified as confounding factors are listed below:

1. Age of instructor (Sproule, 2002)

2. Anonymity (Marsh, 1984)

3. Attractiveness of instructor (Hamermesh & Parker, 2003; Rao, 1995)

4. Availability of course material (Youmans & Lee, 2007)

5. Charisma of lecturer (Naftulin, 1973)

6. Chocolate (Youmans & Lee, 07)

7. Class size (Min & Baozhi, 1998; Light & Cox, 2001)

8. Class time (Zabaleta, 2007)

9. Core or elective module (Marsh and Roche 1997)

10. Course difficulty (Felder, 1992; Felton, Litchell & Stinson, 2004)

11. Course level (Barkhi & Williams, 2010)

12. Discipline (Cerrito, Obenchain, Abernathy, & Wiest, 2001; Felton, Koper, Mitchell, & Stinson, 2008).

13. Easier curricula (Johnson, 2003)

14. Lecturer enthusiasm/expressiveness (Shevlin, Banyard, Davies, & Griffiths 2000).

15. Expected grade (Marsh & Roche, 2000)

16. Experience of instructor (Zabaleta, 2007)

17. Gender of instructor (Basow & Silberg, 1987; Sinclair & Kunda, 2000)

18. Gender of student (Heck, Todd, & Finn, 2002)

19. Grading leniency (Greenwald & Gillmore, 1997)

20. Graduate level of student (Braskamp, Brandenberg & Ory, 1984)

21. How result will be used (Braskamp, Brandenberg & Ory, 1984; Marsh, 1984).

22. Humour (Adamson, O’Kane, & Shevlin, 2005).

23. Instructor’s first language (Zabaleta, 2007)

24. Instructor’s humour & charisma (Adamson, O’Kane, & Shevlin, 2005; Shevlin , Banyard, Davies, Griffiths, 2000)

25. Lecturer status (Braskamp, Brandenberg & Ory, 1984)

26. Lecturer presence (Marsh, 1984)

27. Lecturer rank (d'Apollonia & Abrami, 1997)

28. Lecturer presence during evaluation (Marsh, 1997)

29. Prior experience of subject (Langbein, 2008; Marsh, 1987)

30. Race of instructor (Rao, 1995)

31. Research productivity of lecturer (Cashin, 1988)

32. Sexiness of the professor (Felton, Mitchell, & Stinson, 2004)

33. Student interpretation of SET items (Alderson, 1992; Kalayci, 2009)

34. Student motivation (Langbein, 2008)

35. Students’ expectations of high grades (Worthington, 2002)

36. Surface or deep learners (Entwistle & Tait, 1990)

37. The ‘halo effect’ (Algozzine et al., 2004)

38. Time of day (Greenwald & Gilmore, 1997)

39. Times lecturer taught same course (Marsh and Overall, 1981)

40. Timing, format & distribution of evaluations (Youmans & Lee,2007)


Activity 8.2


Which of the above confounding variables did you most expect to see?

Which of the above confounding variables did you least expect to see?


Select a few variables from the list above that could be classed as either relating to the teacher/lecturer, the student, the module/programme, or administrative factors, and for each one selected suggest one way to control for that factor.


Teacher Factors

Variable Control


Student Factors

Variable Control

Module Factors

Variable Control

Administrative Factors

Variable Control


Back to 8.4 Continue to Section 9 Back To Section 8

Page tools