Contact Information. Paper Titel: "Interaction Patterns in User Interfaces" Authors: Martijn van Welie & Hallvard Traetteberg Email Addresses martijn@cs.vu.nl & hal@idi.ntnu.no Contact Author: Martijn van Welie Division of Mathematics and Computer Science, FEW Vrije Universiteit Amsterdam, The Netherlands 1081 HV Amsterdam email: martijn@cs.vu.nl or martijn@acm.org tel: +31 20 4447788 Abstract: This paper discusses and presents interaction patterns in user interfaces. These patterns are focused on solutions to problems end-users have when interacting with systems. The patterns take an end-user perspective which leads to a format where usability is the essential design quality. The format is discussed and presented along with twenty patterns that have been written in that format.