Ease of Instant Messaging: How the use of IBM Lotus Sametime Changes Over Time
http://www-3.ibm.com/ibm/easy/eou_ext.nsf/Publish/50?OpenDocument&../Publish/1113/$File/paper1113.pdf

IBM
2004

Abstract:

This article discusses the results of surveys that indicate the IBM Lotus Sametime instant messaging product is a successful 'walk-up-and-use' application, requiring little documentation and no training. Users achieve a commercially significant level of performance within three months. In addition, over a much longer period, users continue to develop their skills (chat behaviors), social networks (chat partners), and attitudes toward the technology (reasons for using IM). This combination of attributes — ease of learning and sustained development of skills and strategies — is unusual in Human-computer interaction, and poses some unique challenges for creating a product that experienced users continue to find useful and usable.