1. Albaum, G., Rogers, R.D., Roster, C. and Yu, J.H. (2006), “Simple rating scale formats exploring extreme response”,International Journal of Marketing Research, Vol. 49 No. 5, pp. 633‐50.
2. Reliability and the number of rating-scale categories.
3. Boote, A.S. (1981), “Reliability testing of psychographic scales: five‐point or seven‐point? Anchored or labelled?”,Journal of Advertising Research, Vol. 21, pp. 53‐60.
4. Optimal refinement of the rating scale.