Quality of life is a key criteria in defining and assessing sustainability. There are a range of ways quality of life is measured. A well known method is the Human Development Index (HDI) developed by the United Nations. While this is effective and widely accepted, it is does not capture subjective perceptions of quality of life. Subjective perceptions of quality of life reflect what one feels about your position in the world and your satisfaction with this. Another way of describing this is happiness.
Interesting new research draws on online comments made by people using Twitter to measure what people communicate about themselves. By tracking words like Christmas and mother or hurricane and terror and assigning values to these (1-sad, 9-happy) for about 100 million words a day, the research suggest measures of happiness can be captured over time. The tool developed for this is called the 'Hedonometer' and the results are shown in the graph below.
Of particular interest to the built environment is how this approach can be applied spatially. This is outlined in a paper titled ‘The Geography of Happiness: Connecting Twitter Sentiment and Expression, Demographics, and Objective Characteristics of Place’. Using geotags words are link to locations and mapped, to produce maps of happiness or other social phenomenon such as concerns about obesity. This shown in the map below.
More information on the Hedonometer can be found at: http://www.hedonometer.org/index.html
The paper on the Geography of Happiness can be found at: http://arxiv.org/abs/1302.3299