The choice between a five-point and a ten-point scale in the framework of customer satisfaction measurement

In marketing research, and particularly in the context of customer satisfaction measurement, we often try to measure attitudes and human perceptions. This raises a number of questions regarding appropriate scales to use, such as the number of response alternatives. Obviously, there is a trade-off between the desired response discrimination level and the effort that is demanded of the respondent to situate his or her answer in one of the scale categories. If this effort is too high it can reduce the quality of responses and increase the non-response rate. In the context of customer satisfaction measurement we compare a five-point and a ten-point numerical scale. The analysis includes the evaluation of non-response rates, response distribution, the ability to model customer satisfaction, as well as convergent, discriminant and nomological validity of constructs used in the ECSI (European Customer Satisfaction Index) model. Globally, results tend to favour the choice of the ten-point scale, which contradicts some conventional wisdom. Moreover, we conclude that in this context there are no effects of socio-demographic characteristics (namely educational level) on the ability of respondents to use each scale.