Scales' Polarity
A bipolar scale uses the two theoretical poles of the bipolar concept being measured in the scales’ extremes, for instance, ‘‘satisfied’’ and ‘‘dissatisfied’’.
A unipolar scale uses only one pole of the concept being measured for one extreme and its zero point for the other, for instance, ‘‘important’’ and ‘‘not important at all’’.
A unipolar scale uses only one pole of the concept being measured for one extreme and its zero point for the other, for instance, ‘‘important’’ and ‘‘not important at all’’.
Theoretical arguments
- A disadvantage of bipolar scales is that respondents are reluctant to choose negative responses (Kunz 2015).*
Empirical evidence on data quality
*DeCastellarnau, A. Qual Quant (2018) 52: 1523. doi: 10.1007/s11135-017-0533-4
- Unipolar scales have somewhat higher reliabilities than bipolar scales [Wiley-Wiley reliability] (Alwin 2007). → YES*
*DeCastellarnau, A. Qual Quant (2018) 52: 1523. doi: 10.1007/s11135-017-0533-4
References
Alwin, D.F. (2007). Margins of Error: A Study of Reliability in Survey Measurement. Wiley, Hoboken
Kunz, T. (2015). Rating scales in Web surveys. A test of new drag-and-drop rating procedures. Technische Universität, Darmstadt [Ph.D. Thesis]
Alwin, D.F. (2007). Margins of Error: A Study of Reliability in Survey Measurement. Wiley, Hoboken
Kunz, T. (2015). Rating scales in Web surveys. A test of new drag-and-drop rating procedures. Technische Universität, Darmstadt [Ph.D. Thesis]
