The Source Credibility Matrix

The chart is a four-box grid. Left to right runs from all professional services to agency-specific; bottom to top runs from scheduled hours to work actually delivered. Named sources are plotted as dots, and the two agency-specific, delivered-work sources sit in the top-right box marked directly applicable, while widely quoted sources land in the wrong boxes because they measure the whole professional-services crowd or only scheduled hours. Before you trust a number, check who it was measured on and what it counted; a figure built for every kind of firm isn't a figure about your agency.