1 Interaction CS 7450 - Information Visualization November 4, 2013 John Stasko Interaction? • What do you mean by “interaction”? CS 7450 Fall 2013 22 Background • Interaction (HCI) = “The communication between user and the system” [Dix et al., 1998] = “Direct manipulation and instantaneous change” [Becker et al., 1987] “HCI research is far from having solid (and falsifiable) theories of interaction” [Beaudouin-Lafon, 2004] CS 7450 Fall 2013 3 Clarifying… Interaction Interaction Being interactive, not static Communication, analytic discourse CS 7450 Fall 2013 43 Main Components Fall 2013 CS 7450 5 “The effectiveness of information visualization hinges on two things: its ability to clearly and accurately represent information and our ability to interact with it to figure out what the information means.” S. Few Now You See It, p. 55 “Little Brother” • Two main components in an infovis  Representation  Interaction • Representation gets all the attention • Interaction is where the action is (no pun intended) Fall 2013 CS 7450 64 Research Focus • Very challenging to come up with innovative, new visual representations • But can do interesting work with how user interacts with the view or views  It’s what distinguishes infovis from static visual representations on paper • Analysis is a process, often iterative with branches and side bars CS 7450 Fall 2013 7 Interaction • How do you define “interactive”? CS 7450 Fall 2013 85 One Way: Response Time • .1 sec  animation, visual continuity, sliders • 1 sec  system response, conversation break • 10 sec  cognitive response CS 7450 Fall 2013 9 Example Even simple interaction can be quite powerful Stacked histogram http://www.hiraeth.com/alan/topics/vis/hist.html CS 7450 Fall 2013 106 Fall 2013 CS 7450 Example www.digitalhistory.uh.edu/timeline/timeline.cfm 11 Interaction Types • Dix and Ellis (AVI ’98) propose  Highlighting and focus  Accessing extra info – drill down and hyperlinks  Overview and context – zooming and fisheyes  Same representation, changing parameters  Linking representations – temporal fusion CS 7450 Fall 2013 127 Interaction Types • Keim’s taxonomy (TVCG ’02) includes  Projection  Filtering  Zooming  Distortion  Linking and brushing CS 7450 Fall 2013 13 Another Taxonomy • Operator  navigation, selection, manipulation, distortion, filtering • Space of interaction  screen, data value, data structure, attribute, object, visualization structure • Parameters of the interaction operator  focus, extents, transformation, blender Fall 2013 CS 7450 14 Ward, Grinstein, & Keim 2010, chapter 108 Few’s Principles • Especially useful ways of interacting with data Fall 2013 CS 7450 15 Comparing Sorting Adding variables Filtering Highlighting Aggregating Re-expressing Re-visualizing Zooming and panning Re-scaling Accessing details on demand Annotating Bookmarking Now You See It Chapter 4 Details • Sorting (for example)  Provide a selection of graphs that support the full spectrum of needed comparisons  Provide graphs that are designed for easy comparison of those values and relevant patterns without distraction  Provide the means to place a great deal of information that we wish to compare on the screen at the same time, thereby avoiding the need to scroll or move from screen to screen to see the information Fall 2013 CS 7450 16 Great design checks for your visualization systems9 Challenging • Interaction seems to be a difficult thing to pin down and characterize • Let’s go back to the user trying to solve problems…  User-centered versus system-centered characterizations Fall 2013 CS 7450 17 CS 7450 IEEE TVCG 13(6), ‘07 Fall 2013 18 Another take10 Study Methodology • Survey  59 papers Papers introducing new interaction systems Well-known papers in subareas of Infovis  51 systems Commercial Infovis Systems (SeeIT, Spotfire, TableLens, InfoZoom, etc.)  Collected 311 individual interaction techniques • Affinity Diagram Method CS 7450 Fall 2013 19 Focus Emerged User intent “What a user wants to achieve through a specific interaction technique” CS 7450 Fall 2013 2011 Main Idea • Don’t focus so much on particular interactive operations and how they work • Interaction is ultimately being done by a person for a purpose  Seeking more information, solving a problem  Fundamental aspect of exploratory, analytic discourse Fall 2013 CS 7450 21 Results 7 categories Select Explore Reconfigure Encode Abstract/Elaborate Filter Connect CS 7450 Fall 2013 2212 1. Select “Mark something as interesting” • Mark items of interest to keep track • Seems to often work as a preceding action to subsequent operations. e.g., • Selecting a placemark in Google Map • The Focus feature in TableLens CS 7450 Fall 2013 23 Pop-up tooltips • Hovering mouse cursor brings up details of item CS 7450 Fall 2013 2413 Mouse Selection Clicking on an item selects it and attributes of the data point are shown Selected item Attributes CS 7450 Fall 2013 25 Fall 2013 CS 7450 26 But… What’s wrong with this picture?14 Fall 2013 CS 7450 27 Problem • Where are the labels?  Labeling is difficult to do when so many entities exist  Can add to ball of string problem Fall 2013 CS 7450 28 Objectives • Each label for a data point should:  Be readable  Non-ambiguously relate to its graphical object  Not hide other pertinent information • Completeness (labeling of all objects) is desired but not always possible15 Fall 2013 CS 7450 29 Two types of techniques • Static  Road maps  Physical presentations  Used in cartography • Dynamic  Interactive data points Fall 2013 CS 7450 30 Excentric Labeling Area of focus Line and box color match the color of the data point Description boxes containing the name of the data point Fekete and Plaisant CHI ‘9916 Fall 2013 CS 7450 31 Being Excentric • “Invisible” – Does not appear until user hovers over data points • Describes data points using the name field • Visually connects labels with data points • Can order labels to indicate graph position Demos at http://www.cs.umd.edu/hcil/excentric Generalized Selection • When you click on an item in a visualization, can we generalize the selection off the precise item?  Maybe you want