Bertrand Schneider


Multi-Surface Multi-Touch Simulation of Climate Change and Species Loss in Thoreau’s Woods.

Translating scientific findings into publicly understandable forms is an important step in making science accessible to the general public, thus is crucial in the public awareness of our environment, health and well-being. Visualization can be a powerful tool in achieving this translation. The goal of our research is to use interactive visualization coupled with predictive simulation as a fun and engaging informal learning tool for public informal science education. In this paper, we present WALDEN, an interactive visual simulation as a case study to examine whether a large multi-display multi-touch platform is appropriate for this type of visual informal science education. Our research focuses on the design of an interactive visual simulation system for illustrating and predicting the impact of climate change on the phylogenetic (evolutionary) patterns of species loss in Thoreau’s Woods in Concord, Massachusetts.

Design Requirements

Visualization designed for informal science education audience needs to be illustrative of the core scientific concepts, and also be self-explanatory for non-biologists. For our particular scientific story, we need to (1) present multiple related concepts and parameters including phylogeny, phenology, warming temperatures, and seasonality, and (2) provide visual illustrations such as imageries of flowering plants, geographic distribution of these plants, and the changing climate. To accommodate this large visual content requirement, we employed a multiple display environment that included a multi-touch tabletop (Microsoft Surface) and a large rear projected display wall of 12×6 ft2 (3073 by 1536 pixels).

Two users interacting with WALDEN.

The WALDEN simulation seeks to model changes in abundance of a select group of plants found in Concord, as a response to climate change and human intervention in the local ecosystem. The stochastic simulation uses empirical plant abundance and climate change data observed in Concord over the last ≈100 years, to make future projections on the floral populations in this area.

The abundance change simulation is broken down into three modules: temperature shift (how individual species of plants are able to shift their flowering time (ft) to match fluctuations in annual average temperature; not evolutionary conserved), seasonality (how species are able to respond to fluctuations in temperature from year to year, measured as the standard deviation of average temperatures between years; phylogenetically conserved), and re-growth (the ability of plants to regenerate their populations to their initial equilibrium levels). Each of these modules acts as separate, individual processes that affect the change in abundance of the individual species of plants.

The two screen interfaces of WALDEN.

We carried out two rounds of iterative designs to arrive at the visualization and interaction described. The visualization in Figure 2 illustrates how simulated flower populations are affected by changes in annual average temperature and seasonality. People interacting with the simulation can alter the temperature and seasonality values directly on the multi-touch table, and the effect of these changes are presented on the detailed simulation overview on the large wall display.

Datawall: (A) Cross the top of the data wall, a dynamic scrolling graph displays the simulated annual average temperature (shown as a black graph line), which is superimposed over the simulated seasonality of that period (yellow band). The abundance values of the currently selected species are shown below. Both graphs use a logarithmic scale on the x-axis in order to visualize a longer time period. (B) On the bottom left is a radial phylogenetic tree of the 429 floral species from the Concord area [6]. The simulation only models a subset of these species, and these nodes are identified within the tree by a label presenting the name of the flower and its current abundance value. The currently selected plant species is highlighted in red. (C) On the bottom right, additional information about the currently selected plant species is presented: a map of the species distribution throughout the USA, a scientific drawing of the species, and an example photo image of the flower.

One interaction technique used on the tabletop.

We conducted a qualitative evaluation. The main objective was to assess potential learning gains. In total, 10 users (6 individuals and 2 pairs) participated in the study. We used a think-aloud protocol for prompting comments from individuals. At the beginning of each session, users read a short introduction on phylogeny, and the abstract of Willis’ paper. Our analysis suggests that every user grasped the main idea that closely related plants tend to react in a similar way to climate changes when using the system. Selected quotes from the participants illustrate this understanding: “I notice that similar species seem to be affected in the same way by similar stimulus”, “Species that are close through ancestors have similarities in the abundance behavior”, “Closer species were affected quite similarly by changes in temperature”.

We also noticed that the setup of tabletop/datawall effectively separated action and reflection: users tended to build hypotheses based on their existing pre-conceptions, make changes on the tabletop and then reflect on the results displayed on the large vertical display. Because users had to wait around 10 seconds to see the effect of climate change on the plants, they took advantage of this time to predict the plants’ behavior and elaborate alternative hypotheses.



Schneider, B., Tobiasz, M., Willis, C. & Shen, C. (accepted). WALDEN: Multi-Surface Multi-Touch Simulation of Climate Change and Species Loss in Thoreau’s Woods. ACM International Conference on Interactive Tabletops and Surfaces, ITS  ’12 (pp. 387-390). Boston, MA, USA: ACM.


Project page (SDR lab, Harvard University)


Thanks to Matthew Tobiasz, who built the system; Chia Shen, who funded and supported this wok; Charlie Willis, who provided the scientific evidences on which this project is based; Laurence Mueller, for his moral support.

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