Clear, Tony2015-06-042015-06-042014-12-012014-12-01ACM Inroads, vol.5(4), pp.26 - 272153-2184https://hdl.handle.net/10292/8834An abstract is not available.Authors can post the accepted, peer-reviewed version prepared by the author—known as the "pre-print"—to the following sites, with a DOI pointer to the Definitive Version in the ACM Digital Library.Journal ArticleOpenAccess10.1145/2667234