Scale Comparison

Description

The objective is to evaluate the response format used in some questions of a citizen perception survey about public services. Histograms are used where the number of responses is reduced and visually compared to see if the data distribution resembles the original scale.

Why?

Reducing the number of points in a scale can help reduce response time and increase consistency in participant responses (i.e., they are more likely to respond more authentically). In some cases, these response options are not even used, making them redundant.

Example of three scales with ten, seven, and five points

Method

Using data from the citizen participation survey, the number of responses was reduced to five and seven options. Subsequently, the three versions of the question are plotted in histograms: the original ten-point scale, and the reduced five and seven-point scales respectively. If the graphs of the reduced versions are similar to the original, we can conclude that no information is lost by reducing the scale, which recommends its reduction.

Comparison of the three scales using information on citizens’ perception of water service

When the shape of the reduced scales is different from the original scale, this implies a different interpretation of the results due to information loss. In those cases, it is recommended to keep the original scale.

Comparison of the three scales using results of citizen satisfaction with the quality of traditional public transport service

Results

The following table classifies the results of ten questions focused on citizen satisfaction with public services provided by local government. The results were classified according to the similarity of the histograms of the reduced scales compared to the histogram of the original scale.

Summary of histogram comparison of public service satisfaction indicators
Public Service Five-point scale Seven-point scale
Public lighting Similar Different
Water Similar Identical
Green areas Different Different
Streets and paving Different Different
Electric power Similar Identical
Garbage collection Different Different
Traffic signals Different Identical
Road signs Different Similar
Semi-massive public transport Different Identical
Traditional public transport Different Different

Conclusion

The intention of this analysis is to evaluate whether it is convenient to reduce the original ten-point scale used in the citizen participation survey. Due to the mixed results obtained, it is not recommended to change the original scale. Although there are cases where changing the scale to seven points could be beneficial, using different types of scales can be confusing for the participant and reduce the consistency of their responses.

For more detailed results check: Here