# Exploring Virtual Environments to Assess the Quality of Public Spaces
## 3 Materials and Methods
### Measures: Indicators of Public Spaces Quality
#### 3.3.2 Sustainable Mobility Indicators SUMI  
The Sustainable Urban Mobility Indicator Quality of the public space was the second indicator used for the quantification of our analysis. According to [27], indicators are used to offer technical assistance in assessing urban areas and their urban mobility. The indicators are endorsed and used by the European Commission and are developed based on the \"SMP2.0 Sustainable Mobility Indicators\" developed by the World Business Council for Sustainable Development. The European Commission through the indicators prioritizes supporting European cities in evaluating their mobility system and its sustainability. They also aid cities in tracking the impact of their policies through a widely accepted and harmonized approach.  
The indicators present in the document include the following.  
* Accessibility of public transport for mobility-impaired groups;
* Air pollutant emissions;
* Opportunity for active mobility;
* Multi-modal integration;
* Satisfaction with public transport;
* Traffic safety active modes;
* Quality of public spaces;
* Mobility space usage.  
Between the predeceasing options, only a few were suitable for the premise of our experiment, which is based on the human sensation of public areas such as places, parks, and sidewalks. The most suitable and feasible link between the indicators was the quality of the public spaces indicator. The indicator was designed originally to analyze results from the European Commission's urban audit, a perception survey on the quality of life in European cities which is being conducted by Eurostat based on telephone interviews on a regular basis. The parameter is an averaged score of survey responses conducted by the designer about the perception of satisfaction with public and green spaces.  
The formulation used to compute the indicator from the aforementioned input is the following:  
\[SUMI_{QPS}=\frac{1}{m}\sum_{k=1}^{m}\overline{Aspect}_{k},\]  
m = number of aspects  
aspects = {public spaces, green spaces}  
\(\overline{Aspect}_{k}\) being the weighted average of respondents ratings for aspect \(k\), computed as follow:\[\overline{Aspect}_{k}=\sum_{h}\frac{\text{number of agreement h for aspect m}}{\text{number of respondents}}10C_{h}\]  
with h = strongly agree, \(C_{h}=1\), h= somewhat agree, \(C_{h}=2/3\), h= somewhat disagree, \(C_{h}=1/3\), h= strongly disagree, \(Ch=0\).  
To calculate the indicator, two questions were asked: \"Rate your overall satisfaction with the public spaces available in the area presented\" and \"Rate your overall satisfaction with the green spaces available in the area presented\". In general, public spaces are composed of markets, squares, and pedestrians. While green spaces include parks and gardens. For each of the two questions, the participant had to provide a ranking between 1 and 4, 1 insinuating satisfied and 4 insinuating not at all satisfied; this constitutes the agreement scale. Each possibility was given a fractional weight of ten. For each of the two questions, the number of surveyed participants was input and so was the number of responses for each option (satisfied, rather satisfied, rather unsatisfied, not at all satisfied). Then, based off of this input, two indicator values were computed, one for the public space satisfaction and the other for the green space satisfaction. Then, the average of the two was taken to obtain the final SUMI quality of the public space indicator.