Visual Literacy

Latest published poster: 
Separating the representation from the science:Training students in comprehending 3D diagrams, American Geophysical Union Fall Meeting, 2011.
K. Bemis, D. Silver, J. Chiang, D. Halpern, K. Eun Oh, M. Tremaine.


Visualization Diversity - Measuring the Effect of Spatial Ability Differences in Visualization Comprehension

3-Dimensional visualizations are becoming ubiquitous. Nowadays, not only experts and specially trained personal use 3D visualizations, but the general population is getting exposed to them as well. For instance, 3-Dimensional visualizations are used to provide information about the weather or to illustrate a medical condition to patients.
When this kind of visualizations are used by a population with a broad range of cognitive abilities, comprehension problems arise.

Our goal is to determine how humans understand visualizations and why are visualizations difficult for some. We use well-known individual differences in cognitive skills such as spatial abilities to understand the problems that affect people’s understanding of a visualization.

We plan to run a series of experiments designed to answer fundamental questions such as:

  • Does everyone solve problems similarly?
  • Do they make the same error?
  • How does diversity in the population affect performance in the visualization?
  • Do the solutions proposed help everyone equally?

In our first experiment, we use differences in human spatial abilities to understand the problems that affect people’s understanding of a visualization. Two fundamental aspects that steered the experiment design are:

  • Controlling for human variability makes effects detectable, so we increase variability instead of avoid it. Therefore, we generated a larger effect than the one we would get with a narrow population
  • Looking at extremes helps us understand normal behavior. So, by looking at the behavior of participants at the extremes of the range in spatial ability skills, we can make the influences in visualization more pronounce and therefore easier to detect

This study concentrates on fundamental visualization tasks instead of specific applications. To do that, we have designed a "prototypical" visualization test that asks the experiment participants to form a mental picture of a 3D object based on its 2D projections. We relate this test to standard spatial ability tests and try to understand what makes a particular visualization difficult for different levels of spatial ability.

Fifty-six subjects were tested on a basic visualization task and given standard paper tests of spatial abilities. An equal number of males and females were recruited in this study in order to increase spatial ability variance.

These are the main implications of our results:

  • Spatial abilities are related to 3D visualization comprehension
  • Problem solution time was not found to be related to visualization accuracy
  • Counts of geometric properties affected visualization accuracy for low spatial subjects, and time of analysis for everyone
  • The hidden geometric properties in the visualization affect visualization accuracy for low spatial subjects
  • Small rotation differences are difficult to detect in a visualization
  • A case by case analysis suggests that high spatial and low spatial ability participants use different strategies

This research is supported by the National Science Foundation through the SGER grant #0503680.


Maria Velez, Deborah Silver, Marilyn Tremaine. Understanding Visualization through Spatial Ability Differences. Proceedings of Visualization 2005. IEEE, pages 511-518. Minneapolis, Min. 23-28 Oct, 2005.
Download the presentation and comments (ppt




Collaboration Across Unequal Platforms: The Slow Tetris Project

Because today’s workforce is highly mobile, small wireless devices are being used to support mobile work collaboration. In contrast. individuals in the office invariably have a laptop or a high-end personal workstation and thus, significantly more computing power, more screen real estate, and higher volume input devices, such as a mouse and keyboard. Some of the expected differences in such heterogeneous environments are:

  • Display resolution, size, and aspect ratio
  • Visualization dimensionality (Text-based, 2D, or 3D) and level of detail
  • Computer power
  • Input capabilities
  • Work role (boss to employee, expert to novice)

Our goal in this research was to know what impact these differences have on work performance and work communications. Four different platform combinations involving a PC and a PDA were used to examine the effect of communicating via heterogeneous computer platforms. The PC platform used a mouse, a keyboard, and a 3-dimensional screen display. The PDA platform used a stylus, soft buttons, and a 2-dimensional screen display.

We created a collaborative wall-building game called Slot Tetris. The 3D and 2D version of it is shown in the right figures. The object of the game is to fit a set of odd-shaped blocks together to build a rectangular brick.

We ran two studies in which we had manipulated the participants' role and collaboration tools. 
The first study we created role asymmetry. One subject was arbitrarily put in charge of the task solution in all of the combinations. The conclusions of the free-collaboration study are:

  • Any combination with a platform having a communicator with a poor representation negatively impacts the problem solution even if the partner has a good representation. Any heterogeneous combination with a communicator having the good representation is still somewhat negatively impacted
  • Takeovers were more common when a doer had a platform that was comparable with or better than that of the communicator
  • If one user has a bad platform and is in charge, the communication will change this status. Decisions will be received with less than enthusiastic approval or the role of being in charge will be taken over
  • Given the number of exchanges made in this problem-solving task, this Common Grounding communication was insignificant and we cannot conclude that it had a large impact on our communication exchange
  • The performance time differences appear to be caused by the difficulty of using the platform with the poor representation
  • The PDA->PC communication differences appear to be a result of the role asymmetries combined with the platform asymmetries where the person of higher status is working on a poor platform (e.g., a manager in the field may be communicating with her secretary about appointments, using a PDA)

In the second study, we did not assigned a particular role to participants. Instead, we forced collaboration by assigning different rotation tools to the users, and making the tasks impossible to solve without the use of all the rotation tools. We found that:

  • Larger platforms (PCs) improve performance time even in the case when one partner has a smaller platform (PDA) and the second one has a larger one.
  • Communication patterns were different in the different platform combinations. The patterns are related to how difficult the problem is to solve and to the heterogeneity of the platform combination in the following ways:

    a. If one person has a good representation, the conversation will reflect this person helping the person with the poor representation. This will be represented by an increase in negative politeness commands (for females) or an increase in one-sided direction giving (males).

    b. If both people have a good representation, the task flows smoothly and each person does his or her end of the collaboration. In fact, the flow is so smooth, there may be little to no conversation. This is more pronounced in male teams.

    c. If both people have a bad representation, there is a constant thrashing in the conversation with either person giving up responsibility for solving the problem and asking for help from their collaborator (in the case of males) or with both people talking and continuing to engage in a complete collaborative solution (in the case of females).

    d. When both people work with a difficult representation there are more jokes, more conversation and more common grounding than in other combinations.

This research was supported by NSF Contract No. ANI-01-23910, New Jersey Commission on Science and Technology, and by the Rutgers Center for Advanced Information Processing (CAIP) and its corporate affiliates.


Journal Articles

(Full) Conference Papers - Refereed

Technical Reports

  • M. Velez, M. Tremaine, B. Dorohonceanu, A. Krebs, A. Sarcevic, and I. Marsic. A Study on Heterogeneous Platforms and their Impact on Collaboration. CAIP Report CAIP-TR-265, Rutgers University, June 2002. 

Non-refereed Publications

  • "Neuropsychological diagnostic of visual and spatial agnosias in virtual environments", original title: "Diagnóstico de Agnosias Viso-espaciales mediante Realidad Virtual" at: "VIII Jornada de Investigación". Universidad Pontificia Bolivariana. Medellín, Colombia. August 2000. 
  • "Virtual reality projects in Colombia", original title: "Proyectos de Realidad Virtual en Colombia" at: "Jornada Internacional: Realidad Virtual y la Educación". Antofagasta, Chile. November 1998. 



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