Models for Professional Cyclic Activities in VGI with a Case in Coffee Farming

We argue that an important class of applications of volunteered geographic information is that of professionals reporting on their work, where they did, and how the job was carried out. This is especially useful in the case where those professionals struggle to make a living, as in sub-Saharan agriculture. Conditions in non-mechanised agriculture are highly variable, and 'the local farmer' often operates with non-formalised but specialist understanding of these conditions, and how they need to be negotiated. VGI applications for such farmer communities may help to corroborate that knowledge, and have it fed back to the same communities for further exploitation.
Of special importance in these applications is the notion of repetitive or cyclic activity. In this paper, we present an extended formal framework for these and apply it to a conceptualisation of cyclic, on-farm activities in coffee farming, as typically occurring in sub-Saharan economies. We start by adopting a model of cyclic change to formalise our conceptualisation of on-farm activities, reaching the conclusion that the framework requires extension to allow capturing more of the activity semantics. A proposal is made for that extension, and it includes notions of subcyclic intervals and cyclic aggregations. We subsequently demonstrate these extensions with our conceptualised on-farm activities, and discuss what added functionality they bring to an online information system, under development, that aims to better inform coffee farmers of good practice at designated locations.