The transition from hand-scribed manuscripts to printed books was marked by a quarter-century interaction design lag. This stretch of the 15th century is known for the production of incunabula – printed books lacking the interface design advancements that have since become standard navigational features of book user experience such as page numbering, the table of contents, punctuation, and footnotes.

This lag my be attributed to market expectations – early book consumers wanted books that navigated like the casino online portugal manuscripts that preceded these moveable type facsimiles. Just as early book buyers expected books to work like manuscripts, modern ebook consumers expect ebooks to work like printed books. This has resulted in a wave of electronic incunabula – new platforms lacking interaction design innovations that exploit platform-specific opportunities.