Over the last 10 years, Computer-Supported Cooperative Work (CSCW) has identified a base set of findings. These findings are taken almost as assumptions within the field. In summary, they argue that human activity is highly flexible, nuanced, and contextualized and that computational entities such as information transfer, roles, and policies need to be similarly flexible, nuanced, and contextualized. However, current systems cannot fully support the social world uncovered by these findings. This paper argues that there is an inherent gap between the social requirements of CSCW and its technical mechanisms. The social-technical gap is the divide between what we know we must support socially and what we can support technically. Exploring, understanding, and hopefully ameliorating this social-technical gap is the central challenge for CSCW as a field and one of the central problems for HCI. Indeed, merely attesting the continued centrality of this gap could be one of the important intellectual contributions of CSCW. This paper also argues that the challenge of the social-technical gap creates an opportunity to refocus CSCW as a Simonian science of the artificial.

Ackerman reviews CSCW literature and compiles the findings of over a decade of CSCW research. He identifies the gap between social requirements and technical feasibility as the fundamental problem of CSCW.
According to Ackerman, social activity is flexible, nuanced, contextualized and fluid. People prefer to know who else is present in a shared environment, they are very concerned about how and with whom they wish to share information, and they will sometimes resist articulating their real goals. Therefore, incentives are crucial to the success of CSCW systems. People will not share information if they do not get a benefit or reward.
On the other hand, technical systems are rigid and often awkward to use. It is normally not possible to adjust the level of privacy or awareness. People might want their co-workers to know whether they are online but not their manager. Other problems of CSCW systems are for example concurrency issues - several persons work on the same document, and the lack on contextual information - informal communication is missing in CSCW environments, distant co-workers are often more heterogeneous in terms of both knowledge and skills.
The article provides hints on how to overcome some of the shortcomings of CSCW. Features like chat, buddy-list and other communication tools help people to feel less distant and to share a certain amount of context. Ackerman calls these features “first-order approximations” because they do not solve the major problems of CSCW but approximate real-life social settings. He then argues that the socio-technical gap creates an opportunity for CSCW to become a true "science of the artificial", a term introduced by Herbert Simons in 1969.
Ackerman has written a concise overview of CSCW. Novices get a useful introduction to the social and technical findings of the field. The author illustrates clearly that CSCW has an inherent socio-technical gap that cannot be bridged by some merely technical means. However, the call for a CSCW science is slightly exaggerative. [from http://www.elearning-reviews.org/topics/human-computer-interaction/usability/2000-ackerman-intellectual-challenge-cscw/]