Mark O'Donovan is a Qlik Developer based in London, England. Mark has over 20 years' experience in the IT industry and has been working on Sql Server Business Intelligence projects since 2008 and using QlikView since version 9. He has had an interest in visualization since his Master's degree thesis called 'Towards a methodology for visualizing quantum computing' which was presented as part of a EuroGraphics conference at Imperial College, London in 1996. Mark has been an active member of the Qlik Community since October 2011 and has been the Author\Publisher (TechStuffy Books) of the following books on Qlik and Sql: Qlik Sense for Beginners Practical QlikView Practical QlikView 2 - Beyond Basic QlikView Practical Sql: Microsoft Sql Server T-SQL for Beginners