undocumentable

un- +‎ documentable

undocumentable (not comparable)

1. Not supportable with documentary evidence.

   These hearsay claims are intrinsically undocumentable.

   • 1953, W. Cochran, F. Mosteller, and J. Tukey, "Statistical Problems of the Kinsey Report," Journal of the American Statistical Association, vol 48 no 264 (Dec), p. 674.

     KPM should have indicated which of their statements where undocumented or undocumentable and should have been more cautious.

   • 1972, W. E. Fredeman, "Impediments and Motives: Biography as an Unfair Sport," Modern Philology, vol 70 no 2 (Nov), p. 151.

     . . . that undocumentable life of which, Sonstroem repeatedly acknowledges, he may not himself even have been aware.

   • 1997, Stephen Jay Gould, "Editorial: Bright Star Among Billions," Science, vol 275 no 5300 (31 Jan), p. 599.

     Real science is so damned exciting, transforming, and provable, why would anyone prefer the undocumentable nonsense of astrology, alien abductions, and so forth?

   • 2002, Scott Moss, "Policy analysis from first principles." Proceedings of the National Academy of Sciences, vol 99, no 10, sup 3 (May), p. 7265.

     Apart from one undocumentable claim, the strongest responses were that, when applied to past data, some new modeling techniques look better than most previous modeling techniques.

• documentable