Abstract. Wikidata is a collaboratively-edited knowledge graph; it expresses knowledge in the form of subject-property-value triples, which can be enhanced with references to add provenance information. Understanding the quality of Wikidata is key to its widespread adoption as a knowledge resource. We analyse one aspect of Wikidata quality, provenance, in terms of relevance and authoritativeness of its external references. We follow a two-staged approach. First, we perform a crowdsourced evaluation of references. Second, we use the judgements collected in the first stage to train a machine learning model to predict reference quality on a large-scale. The features chosen for the models were related to reference editing and the semantics of the triples they referred to. 61% of the references evaluated were relevant and authoritative. Bad references were often links that changed and either stopped working or pointed to other pages. The machine learning models outperformed the baseline and were able to accurately predict non-relevant and nonauthoritative references. Further work should focus on implementing our approach in Wikidata to help editors find bad references.

The use of game elements within virtual citizen science is increasingly common, promising to bring increased user activity, motivation and engagement to large-scale scientific projects. However there is an ongoing debate about whether or not gamifying systems such as these is actually an effective means by which to increase motivation and engagement in the long term. While gamification itself is receiving a large amount of attention, there has been little beyond individual studies to assess its suitability or success for citizen science; similarly, while frameworks exist for assessing citizen science performance, they tend to lack any appreciation of the effects that game elements might have had. We therefore review the literature to determine what the trends are regarding the performance of particular game elements or characteristics in citizen science, and survey existing projects to assess how popular different game features are. Investigating this phenomenon further, we then present the results of a series of interviews carried out with the EyeWire citizen science project team to understand more about how gamification elements are introduced, monitored and assessed in a live project. Our findings suggest that projects use a range of game elements with points and leaderboards the most popular, particularly in projects that describe themselves as 'games'. Currently, gamification appears to be effective in citizen science for maintaining engagement with existing communities, but shows limited impact for attracting new players.

Abstract. This paper describes three tools that have been developed to help overcome accessibility, usability and productivity issues identified by disabled students. The Web2Access website allows users to test any Web 2.0 site or software application against a series of checks linked to the WCAG 2.0 and other guidelines. The Access Tools accessible menu helps with navigation to portable pen drive applications that can assist with accessibility, productivity and leisure activities when on the move. The accessible Toolbar provides support for the majority of browsers and accessible websites through magnification, spellchecking, text to speech readout, dictionary definitions and referencing modification of text, page style, colour and layout.

In this paper, we describe three tools that facilitate 'crowdsourcing' open source development to help overcome accessibility, usability and productivity issues identified by disabled students.