Information Visualization http://ivi.sagepub.com/ Innovation trajectories for information visualizations: Comparing treemaps, cone trees, and hyperbolic trees Ben Shneiderman, Cody Dunne, Puneet Sharma and Ping Wang Information Visualization 2012 11: 87 originally published online 16 November 2011 DOI: 10.1177/1473871611424815 The online version of this article can be found at: http://ivi.sagepub.com/content/11/2/87 Published by: http://www.sagepublications.com Additional services and information for Information Visualization can be found at: Email Alerts: http://ivi.sagepub.com/cgi/alerts Subscriptions: http://ivi.sagepub.com/subscriptions Reprints: http://www.sagepub.com/journalsReprints.nav Permissions: http://www.sagepub.com/journalsPermissions.nav Citations: http://ivi.sagepub.com/content/11/2/87.refs.html >> Version of Record - Apr 9, 2012 OnlineFirst Version of Record - Nov 16, 2011 What is This? Downloaded from ivi.sagepub.com at University of North Carolina at Chapel Hill on April 9, 2012 Article Information Visualization 11(2) 87–105 Ó The Author(s) 2011 Innovation trajectories for information Reprints and permissions: sagepub.co.uk/journalsPermissions.nav visualizations: Comparing treemaps, DOI: 10.1177/1473871611424815 cone trees, and hyperbolic trees ivi.sagepub.com Ben Shneiderman1, Cody Dunne1, Puneet Sharma1 and Ping Wang2 Abstract This paper reviews the trajectory of three information visualization innovations: treemaps, cone trees, and hyperbolic trees. These three ideas were first published around the same time in the early 1990s, so we are able to track academic publications, patents, and trade press articles over almost two decades. We describe the early history of each approach, problems with data collection from differing sources, appropriate metrics, and strategies for visualizing these longitudinal data sets. This paper makes two contributions: (1) it offers the information visualization community a history of how certain ideas evolved, influenced others, and were adopted for widespread use and (2) it provides an example of how such scientometric trajectories of innova- tions can be gathered and visualized. Guidance for designers is offered, but these conjectures may also be useful to researchers, research managers, science policy analysts, and venture capitalists. Keywords information visualization, innovation trajectories, graphical user interfaces, treemap, cone tree, hyperbolic tree Introduction to familiar problem-solving strategies7 andworkprac- The healthy outpouring of innovations from the infor- tices. These critics advocate extended case studies with mation visualization community has raised important users who work for weeks and months using the inno- questions about how to measure the efficacy, adoption, vative visualization on their own tasks. Longer term and durability of these innovations. These measures measures of efficacy account for other changes such as could help retrospective analyses that seek to compare improved interfaces, better training, simpler integra- several technologies, but the greatest interest is pre- tion with other tools, and a community of like- dictive models that forecast eventual impact of novel minded users who are capable of discussing advanced technologies. This goal may be difficult to attain, uses of an innovative visualization. Evaluations of effi- but simpler descriptive and explanatory theories can cacy often lead to refinements and clarification of be helpful to guide future entrepreneurs,1 corporate which tasks are more assisted, and provide a basis research managers,2 government funding agency for promoting an innovation. staff,3 and historians of science as they seek to under- Measuring adoption (also called acceptance or stand the evolution of technology.4,5 Another goal is to diffusion) beyond the originators is also a challenge develop prescriptive theories based on these metrics, as innovations may spread in different ways.8 which suggest guidance and policies for promoting technological innovations. 1Department of Computer Science and Human–Computer Initial questions of efficacy can be partially settled Interaction Lab, University of Maryland, College Park, MD, USA by empirical testing with traditional controlled experi- 2College of Information Studies and Human–Computer Interaction ments with a few dozen subjects for a few hours that Lab, University of Maryland, College Park, MD, USA compare an existing visualization against the innova- tion.6 Critics of this approach suggest that short train- Corresponding author: Ben Shneiderman, Department of Computer Science and Human– ing periods with standard tasks are insufficient to Computer Interaction Lab, University of Maryland, College Park, test innovations that may require more substantial MD 20742, USA training, a wider variety of tasks, and even changes Email: [email protected] Downloaded from ivi.sagepub.com at University of North Carolina at Chapel Hill on April 9, 2012 88 Information Visualization 11(2) Simple measurements in the 2–5 years following the A secondary measure is the number of citations to initial presentation of an innovation include the key academic papers and patents. We use these mea- number of references in later papers, implementa- sures and other sources to try to explain the relative tions by multiple open-source or commercial organi- success of innovations and give guidance to promoters zations, and use by a growing set of users. Some of information visualization innovations. impacts are more noteworthy than others, such as A still more difficult goal is to use early measures to solving important problems, sales of commercial predict which future information visualization innova- products, or inspiring further innovations. tions will become successful. This latter goal is aligned However, impacts may take years or decades to with current US National Science Foundation efforts emerge and innovations may need much transforma- to develop a ‘Science of Science’, which would help tion or integration with other ideas to have impact. program managers allocate funding more effectively The longer term (5–15 years) diffusion through orga- to high-payoff research proposals. nizations, industries, and countries is likely to be seg- This paper begins with a personal historical review of mented, as in reaching novice or experienced users, tree browsing and visualization methods that focuses on professionals or consumers, and old or young users. treemaps, cone trees, and hyperbolic trees. Then it dis- The Technology Acceptance Model9 focused on per- cusses how to gather data for tracking the trajectory of ceived usefulness and perceived ease of use, but later these methods from academic publications to commer- versions incorporated other parameters.10 cial applications, followed by data visualization to show Measuring durability (also called sustainability) over these trajectories. The discussion provides guidance to decades is important in understanding why innovations designers and the conclusion discusses the difficulty of lose their enthusiastic advocates or satisfied users, how such reviews, lessons learned, and future work. later innovations replace earlier innovations, and how innovations become so accepted as to become invisible, Tree browsing and visualization unmentioned, and taken for granted. These measures may be difficult to capture, difficult Even early uses of computers, such as Doug Engelbart’s to compare, imprecise, and unstable over time. For famous 1968 demonstration of his Augment system example, the number of websites mentioning an inno- presented strategies for browsing tree-structured infor- vation began to be relevant only by the later 1990s, mation, often described as hierarchies. Some tree brow- so comparisons with earlier innovations are difficult. sers simply used indented textual representations, Download counts for some software are useful, but which became standard in many directory browsers sometimes a few hundred downloads by valued users such as Microsoft Windows Explorer. Indented textual can be a success whereas in other situations millions of representations are highly effective because they allow downloads may be needed to claim success. rapid scanning down lists, alphabetical ordering, and Another class of difficulties relates to names used comprehensible expand/contract strategies to support when using search engines, digital libraries, or data- exploration. The disadvantages include the need for bases. Some innovations have distinct names that are frequent scrolling as the number of nodes grows and easy to track, whereas others have generic names that the difficulty in discovering large subtrees that might be are harder to search for. An innovation may be given several levels down. different names by those who make refinements or The appeal of graphical user interfaces encouraged brand names for commercial purposes, meaning that many developers to create node-link diagrams, which credit is less easily tied to the originators. Often an became widely used during the 1980s. These visualiza- innovation becomes integrated in a larger product so tions were readily understandable, whether drawn with it is difficult to track. the root node at the top, bottom, left side, or right side. This paper uses counts of academic papers, patents, With small trees of 10–50 nodes this strategy was effec- and trade press articles as measures to describe tive, but with larger trees that had large depth (many the innovation trajectories of three tree visualization levels) or high