Designing annotation tools based on properties of annotation problems D. Reidsma, N. Jovanovic and D. Hofs Department of Electrical Engineering, Mathematics and Computer Science, University of Twente, Enschede, The Netherlands The creation of large, richly annotated, multimodal corpora of human interactions is an expensive and time consuming task. Therefore, support from annotation tools that make the annotation process more efficient is required, especially if the annotation effort involves really large amounts of data. Tools which are very efficient for one particular annotation task are not necessarily so for other tasks. Making one tool to handle every conceivable annotation will result in a monolithic, unwieldy tool. Therefore we investigated how different properties of specific annotation tasks can have an impact on the design of a tool focused on that general class of tasks. In this paper we present our view on the considerations that should drive the design of new tools geared to specific tasks.. Paper presented at Measuring Behavior 2005 , 5th International Conference on Methods and Techniques in Behavioral Research, 30 August - 2 September 2005, Wageningen, The Netherlands. © 2005 Noldus Information Technology bv