In GUI bloopers, consultant Jeff Johnson uses 550 + pages to illustrate common pitfalls in user interface design, an important tip of the iceberg-all end-users are confused with application developers and are confused with the end user. 82 incident reporting bad design, Johnson managed to close the critical point of his message: software designers should think of their user interface from a user standpoint. His codification of GUI design in eight principles are expected to help the GUI newbies realize that customers should be pleased with the product. When the customer is not at hand, a replacement will be done, so that usability testing is important. The bloopers include mistakes in the design window, labeling consistency, visual / grammatical parallel construction, coherence of look and feel, and clarity. Most perceptively, Johnson observes that the CPU speed in the development group hides many design mistakes. In addition, context-scoping, already a subtle problem in software design, should be applied in GUI design. User error messages can easily be too vague or too specific, and diagnostic error messages should be user-managed, if not actually user-interpreted. As Hollywood outtakes that give us "blooper," the results for the entertainment here is measured in error, not success.