While the use of health IT applications has increased rapidly over past decades, this does not compare strongly with other business sectors. Both reluctance to invest in, and lack of demand to use IT systems may in part be due to lack of robust evidence as to proven benefits. At the same time, the health IT sector has lagged behind other health technology areas in working to, and being expected to work to, robust evidence standards showing benefit and also avoidance of harm. Exacerbating this, limited availability of evidence has perpetuated this misplaced comfort in use of aspiration and expectation rather than evidence in driving investment in health IT applications. Reference back to the core principles drawn from influential thinkers shows the essential centrality of the need for evidence of safety and effectiveness, and for its use relevantly related to context.