Abstract: Many studies cite Katz and Allen (1982) as a of Not-Invented-Here (NIH) syndrome. However, their validation is misled by 1) easily adopting a smoothing method on a scatter diagram with no clear trends, and 2) arbitrarily choosing intercept on y-axis. The greatest mystery is that Katz and Allen (1982) used to refer to a decline in project performance caused by length of project members' tenure. In spite of fact that is normally considered to refer to self-sufficiency, Katz and Allen (1982) had used it to refer to decline in performance brought about by length of service of project members. However, real mystery is that many researchers continue to cite this as a study advocating self-sufficiency.Keywords: Not-Invented-Here syndrome, project tenure, communication, RD Allen was one of researchers pivotal to this work (Kuwashima, 2012). Allen and Cohen (1969) and Allen (1977) are known for identifying existence and effectiveness of gatekeeper in research and development organizations. Even recently in Japan, this concept inspires a lot of research, for example, Harada (1999), Kuwashima, Takahashi, and Tamada (2005), Inamizu and Wakabayashi (2009).In late 1970s, Allen and others embarked on a large-scale research project investigating R&D facility in a major company to examine gatekeeper concept in more detail. Results from this study were published in succession from late 1970s to early 1980s: Tushman (1978), Allen, Tushman, and Lee (1979), Tushman (1979), Tushman and Katz (1980), Tushman and Scanlan (1981a) and Katz (1982). Except for Tushman and Scanlan (1981b) and Tushman and Romanelli (1983), most of these publications all came out of this one project.Katz and Allen (1982) is one of final papers published from this research project. The content of Katz and Allen (1982) is almost identical to Katz (1982), which was published same year. These papers show an inverse-U-shaped graph of project performance against mean project of R&D project members. However, Katz (1982) only seldom uses term NIH syndrome as one interpretation of analysis results. Strangely, on other hand, Katz and Allen (1982) highlighted that term, as seen in title, publishing now well-known Figure 4 of the relationship between mean group and project performance analyzed into its components as validation. As a result, this paper became most-cited study on (Lichtenthaler & Ernst, 2006).The found in Katz and Allen (1982) is not self-sufficiency, as often quoted, but in fact, simply in performance caused by long project tenure as mentioned above. This paper makes it clear that Katz and Allen's results were misled by easy adoption of a smoothing method and arbitrary choice of intercept on y-axis.NIH SyndromeThe abstract at beginning of Katz and Allen (1982) defines as the tendency of a project group of stable composition to believe it possesses a monopoly of knowledge of its field, which leads it to reject new ideas from outsiders to likely detriment of its performance.The study investigates all 345 R&D professionals in R&D facility in a major company. Each staffmember is assigned to and stays with one of 61 projects for duration of study. The completed data were taken from 50 project groups, which equates to 82%.(a) The mean (x) of project team members: This is mean period for which project team members interact with each other, rather than period of duration of project. Technical communication data were collected over a period of 15 weeks on a randomly selected day each week. …