1InteractionCS 4460/7450 - Information VisualizationFeb. 24, 2009John StaskoInteraction?• What do you mean by “interaction”?CS 4460/7450Spring 2009 22Background• Interaction= “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 4460/7450Spring 2009 3Clarifying…InteractionInteractionBeing interactive, not staticCommunication, analytic discourseCS 4460/7450Spring 2009 43“Little Brother”• Two main components in an infovis− Representation− Interaction• Representation gets all the attention• Interaction is where the action is (no pun intended)CS 4460/7450Spring 2009 5Research 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 barsCS 4460/7450Spring 2009 64Interaction• How do you define “interactive”?CS 4460/7450Spring 2009 7Response Time• .1 sec− animation, visual continuity, sliders• 1 sec− system response, conversation break• 10 sec− cognitive responseCS 4460/7450Spring 2009 85ExampleEven simpleinteractioncan be quitepowerfulStacked histogramhttp://www.hiraeth.com/alan/topics/vis/hist.htmlCS 4460/7450Spring 2009 9Spring 2009 CS 4460/7450Examplewww.digitalhistory.uh.edu/timeline/timeline.cfm106Interaction 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 fusionCS 4460/7450Spring 2009 11Interaction Types• Keim’s taxonomy (TVCG ’02) includes− Projection− Filtering− Zooming− Distortion− Linking and brushingCS 4460/7450Spring 2009 127CS 4460/7450IEEE TVCG 13(6), ‘07Spring 2009 13Another takeStudy Methodology• Survey− 59 papersPapers introducing new interaction systemsWell-known papers in subareas of Infovis− 51 systemsCommercial Infovis Systems (SeeIT, Spotfire, TableLens, InfoZoom, etc.)− Collected 311 individual interaction techniques• Affinity Diagram MethodCS 4460/7450Spring 2009 148Focus EmergedUser intent“What a user wants to achieve througha specific interaction technique”CS 4460/7450Spring 2009 15Main 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− Fundamental aspect of exploratory, analytic discourseSpring 2009 CS 4460/7450 169Results7 categoriesSelectExploreReconfigureEncodeAbstract/ElaborateFilterConnectCS 4460/7450Spring 2009 171. 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 TableLensCS 4460/7450Spring 2009 1810Pop-up tooltips• Hovering mouse cursor brings up details of itemCS 4460/7450Spring 200919Mouse SelectionClicking on anitem selects itand attributesof the data point are shownSelected itemAttributesCS 4460/7450Spring 2009 2011Spring 2009 CS 4460/7450 21But…What’s wrong with this picture?Spring 2009 CS 4460/7450 22Problem• Where are the labels?− Labeling is difficult to do when so many entities exist− Can add to ball of string problem12Spring 2009 CS 4460/7450 23Objectives• 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 possibleSpring 2009 CS 4460/7450 24Two types of techniques• Static − Road maps− Physical presentations− Used in cartography• Dynamic − Interactive data points13Spring 2009 CS 4460/7450 25Excentric LabelingArea of focusLine and box color match the color of the data pointDescription boxes containing the name of the data pointFekete and Plaisant CHI ‘99Spring 2009 CS 4460/7450 26Being 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 positionDemos at http://www.cs.umd.edu/hcil/excentric142. Explore “Show me something different”• Enable users to examine a different subset of data• Overcome the limitation of display sizee.g.,• Panning in Google Earth• Direct Walking in Visual ThesaurusCS 4460/7450Spring 2009 27Direct Walk• Linkages between cases• Exploring one may lead to another• Example:− Following hyperlinkson web pagesCS 4460/7450Spring 20092815ExampleVisual ThesaurusSpring 2009 CS 4460/7450 29http://www.visualthesaurus.com3. Reconfigure“Show me a different arrangement”• Provide different perspectives by changing the spatial arrangement of representatione.g., • Sorting and rearranging columns in TableLens• Changing the attributes in a scatter plot• The baseline adjustment feature in Stacked Histogram• The “Spread Dust” feature in Dust & MagnetCS 4460/7450Spring 2009 3016Rearrange View• Keep same fundamental representation and what data is being shown, but rearrange elements− Alter positioning− SortCS 4460/7450Spring 2009 31ExampleStacked HistogramSpring 2009 CS 4460/7450 3217RearrangeIn TableLensyou can movecolumns (attributes)left and rightCS 4460/7450Spring 2009 33SortingCan sort data with respect to a particularattribute in Table LensCS 4460/7450Spring 2009 34184. Encode“Show me a different representation”• Change visual appearancese.g.,• Changing color encoding• Changing size• Changing orientation• Changing font• Changing shapeCS 4460/7450Spring 2009 35Changing Representation• May interactively change entire data representation− Looking for new perspective− Limited real estate may force changeCS 4460/7450Spring 2009 3619ExampleSelecting different representation from options at bottomCS 4460/7450Spring 2009 375. Abstract/Elaborate“Show me more or less detail”• Adjust the level of abstraction (overview and details)e.g.,• Unfolding sub-categories in an interactive pie chart• Drill-down in Treemap•