Figure 1. Diagram representing the phases of the work presented in this paper, with the research objectives.
The paper is organized as follows: in Section 2 we present the background of this study by diving in different aspects of the Wikipedia language communities that we measured. In Section 3, we present the approach and we define how we measure the growth and renewal of the communities and how we set-up the validation for the final indicators. In Section 4, we present the results of the measurements for a set of eight languages and the feedback provided by the language communities and affiliates. In Section 5, we discuss the main results as well as potential uses of the indicators, to finally state the limitations of the study. Finally, in Section 6, we draw some conclusions.
2. Background
2.1. Communities Decline and Stagnation
The number of contributors to the English Wikipedia grew until March 2007, when it began to rapidly decline until 2014 [14,15]. Other language editions like German, Spanish, Italian or French stopped their growth between 2007 and 2011. Hill and Shaw [16] found that other active peer production communities (open-source software commons) often experience a period of rapid growth followed by stabilization.
Stagnation in terms of the number of active editors in the English Wikipedia has become common in general and specialized press for more than a decade. It has been taken for granted as much as Wikipedia’s value to society. Even though it appears that Wikipedia communities have a delicate but basically sound constitution, we do not know the risks involved in stagnation.
In this Section, we want to understand how past research explains the factors related to this decline in the number of active editors. Ultimately, our first objective is to describe the state of the active community for all languages, whether it is growing, stagnant, or declining.
2.1.1. Bureaucracy and Openness
One desirable explanation to why Wikipedia communities peak and decline would be that there comes a time in which most of the current knowledge has already been documented in the form of articles and structured data. However, we argue that this is not the case, given the diverse coverage of topics and the size of the different Wikimedia projects with a stagnant community. On the contrary, the wideness of accepted topics might provide a reason for editors to stay. Asatani et al. [17] suggest that communities allowing free-topic do not tend to collapse (i.e., to lose their users suddenly).
While topic availability or exhaustion can hardly explain this decline, observed for encyclopedias of very different sizes, we might think that the number of potential contributors in a society plays a role in community growth. Even though this might be true for small languages, on the other hand, we see that some large linguistic communities like German or French exhibit the same stagnation pattern. Therefore, we might incline
