Professional development to support teachers in using technology is not new. The British Journal of Educational Technology was first published in 1970, and a seventeen-nation European project to bring together expertise in this field was published over twenty-five years ago (Harrison, 1988). Unfortunately however, educational research has not kept pace with technological change, and while online teacher professional development (oTPD) has increased exponentially, evidence of the effectiveness of such self-directed learning is often anecdotal and based on immediate rather than long-term impact (Dede, 2009). The MESH Guides (2014) are part of an international oTPD initiative offering teachers quick access to research-informed professional knowledge, and this presentation shares findings from an evaluation of the MESH Spelling site, a suite of resources on cognition and spelling development, with lesson plans and software, all aimed at helping teachers of English improve their students’ spelling. The site collects data on user nationality, navigation, behaviour flow and event timing, augmented by a questionnaire that probes deeper issues of perceived usefulness and learning. This presentation reports data from teachers in the UK, USA, China, Malawi and Nigeria, and attempts to document some of the cultural as well as pedagogical challenges of conducting an intercontinental online evaluation.