StopDesign : The I.E. Factor

IE/Win will defy all common logic. Which makes it such a difficult browser to troubleshoot. I don’t dwell on the box model problems in version 5.x. Those can be dealt with. It’s the idiosyncrasies of IE5.0, IE5.5, and IE6.0 together (or in different combinations) that will drive a CSS author mad. (…)

In reality, I’ve now calculated the IE Factor can add upwards of an additional 10% in time and cost for each project, distorting the estimating process if it’s not figured in.