Studying the spatial distribution of volunteered geographic data through a non-parametric approach

Nowadays, new knowledge on the immaterial characteristics of surrounding landscapes can easily be produced by relying on volunteer contributions. However, the spatial distribution of the collected data may be influenced by the contributor’s location. Using data sets derived from the administration of a map-based survey, aimed at collecting explicit spatial information on sites perceived as having positive and negative qualities in Friuli Venezia Giulia (Italy), a descriptive analysis and a non-parametric procedure are employed to study the relevance of a respondent’s municipality of reference on the mapping activity. The findings indicate that the volunteered geographic data collected in the survey are not uniformly distributed across the study area and that a different spatial relationship exists between mapped elements and a respondent’s residence when the two different attributes of interest are considered. The results underline the importance of considering volunteers’ characteristics when engaging local populations in participatory initiatives.