Scales' Symmetry
Symmetry is a specific characteristic of bipolar scales. Symmetric scales assure that the number of labels in bipolar scales is the same in the positive and in the negative side.
Theoretical arguments
- An asymmetric scale presupposes knowledge about the opinion of the sample, otherwise it is biased (Saris and Gallhofer 2014).*
Empirical evidence on data quality
YES means that there is an effect on quality either positive or negative impact. NO means that there is no effect.
*DeCastellarnau, A. Qual Quant (2018) 52: 1523. doi: 10.1007/s11135-017-0533-4
- Symmetric scales have a positive effect on reliability and validity [True-score MTMM reliability and validity] (Saris and Gallhofer 2007) →YES*
- Reliability and validity are slightly higher for asymmetric scales [True-score MTMM reliability and validity] (Scherpenzeel and Saris 1997) → NO*
YES means that there is an effect on quality either positive or negative impact. NO means that there is no effect.
*DeCastellarnau, A. Qual Quant (2018) 52: 1523. doi: 10.1007/s11135-017-0533-4
References
Saris, W.E., Gallhofer, I.N. (2007). Design, Evaluation, and Analysis of Questionnaires for Survey Research. Wiley, Hoboken.
Saris, W.E., Gallhofer, I.N. (2014). Design, Evaluation, and Analysis of Questionnaires for Survey Research. Wiley, Hoboken.
Scherpenzeel, A.C., Saris, W.E. (1997). The validity and reliability of survey questions: a meta-analysis of MTMM studies. Sociol. Methods Res. 25, 341–383.
Saris, W.E., Gallhofer, I.N. (2007). Design, Evaluation, and Analysis of Questionnaires for Survey Research. Wiley, Hoboken.
Saris, W.E., Gallhofer, I.N. (2014). Design, Evaluation, and Analysis of Questionnaires for Survey Research. Wiley, Hoboken.
Scherpenzeel, A.C., Saris, W.E. (1997). The validity and reliability of survey questions: a meta-analysis of MTMM studies. Sociol. Methods Res. 25, 341–383.
