Conclusions - Human-Computer Interaction - page 172

Another challenge is related to authoring and publishing. On the one hand, appli-
cations should enable end-users to easily create their own pen-enabled documents
and paper interfaces. While for a long time, this was possible only with research pro-
totypes, first commercial applications targeting at end-users are now issued on the
market. On the other hand, current pen-enabled print products are closed solutions.
Only if a user disposes of the specific application that belongs to the product, he or
she can interact with the print product. However, a mass market of pen-enabled print
products requires interoperability between different applications. In this context, a
service-based approach seems promising [136, 36].
Better Understanding of Long-term Usage
Finally, we have seen that, even though a large number of Pen-and-Paper Interfaces
have been developed over the past years, there is only very little research that exam-
ines how people use these interfaces. Only a very small number of studies examine
how Pen-and-Paper Interfaces are used over a longer period of time and how they
get integrated into existing information ecologies [89, 149, 147]. There is a clear
need for a better understanding of how interfaces are used over longer periods of
time and how they affect our work practices. This will take us another step further
on the challenging and exciting journey towards closing the gap between printed
and digital documents.