Measuring XML schema standard quality change through versioning

Quality measurements of XML schemas are difficult to perform objectively, providing all aspects of quality demands. However, an approximate evaluation of XML schema´s quality and validation, whether a higher version of an XML schema standard is in fact an improvement, is useful information for XML schema users. The paper addresses who are the users of XML schemas, what aspects of XML schemas are vital to its quality and how to measure those aspects. We present 3 quality aspects in more detail: (1) structure type, (2) re-use possibilities and (3) balance of building blocks. A table of all included variables, that were measured, is provided. Based on results of over 200 XML schemas, quality assessment are given, including data standardization methods. Measurement results of XML schema´s versions are compared, providing insight into quality growth (or decline) through versioning.