Taxonomic units

One important consideration in taxonomic information is that the model that most people learn about taxonomic groupings is inconsistent with the way that the species are currently classified. This creates a conflict between what taxonomic information users expect to see and how it should be classified by real distinctions between species. After the interviews that I conducted I determined that users tended to conceptualize information according to the Linnaean classification system. In particular users thought about the information in terms of the taxonomic units:

• Class
• Genus
• Species

For this reason I have decided to have the introduction to the information visualization system beginning with class data. The exact classes chosen should be based on classes. However there are far more classes than can be easily represented on a screen. I choose several based on the suggestions of the zoologists at the ADW. The hope is that these classes will help users orient themselves to the data by providing familiar groupings. The class should also be displayed in a way that presents the respective sizes of the classes. The visualization above is an attempt to visualize the selected classification data.

Visualizing Sizes of Taxonomic Units

The goal for this week was to display the size for each taxonomic unit. While displaying size is simplistic, representing size in a manner that allows the tree to remain continuously represented posed some challenges. After sketching I settled on this design for several reasons.

1. The representation allows the user to see the relation between the tree and the size simultaneously
2. Representing the size doesn't distort the taxonomy information
3. The linear representation of size allows for easy comparison between taxonomic units

The major detriment is that it takes up more horizontal screen real estate than would be ideal. This problem could be lessened by repositioning the text.

Visualizing Trees

These sketches demonstrate some of the trade-offs involved in visualizing taxonomic trees. In classic taxonomic trees the parent taxa intersects the branch in the center (illustration on the left) . While this system has the benefit of following a convention it resulted in trees that required much more horizontal screen real estate. To counter this I choose to use the indented tree lay out (illustration on the right)

This mock up demonstrates a more complete model of the visualization system's interface.

Overview

Animal Diversity Web (ADW) is an online database of animal natural history, distribution, classification, and conservation biology at the University of Michigan. One goal of the ADW is to provide Tools for science learning. ADW facilitates inquiry-driven learning, that is, teaching about science by leading students to use the methods of science. Our large database is structured, providing consistent information for all species to foster comparisons. An advanced search tool allows a user to call up species accounts fitting any combination of descriptors. Students can explore for patterns and relationships, learn how to frame and answer scientific questions and, with the help of a good teacher, experience the excitement and satisfaction of doing science. Our long-term goal is to create a database rich enough that students can discover for themselves basic concepts in ecology and conservation biology.

To facilitate this goal I am developing a visualization tool that will help users locate species and make inferences about the relationships between items in the collection. This will done with a interactive treemap based on the Prefuse Flare visualization tool. Flare is a collection of ActionScript 3 classes for building a wide variety of interactive visualizations including basic charts, complex animations, network diagrams, treemaps, and more. Flare is written in the ActionScript 3 programming language and can be used to build visualizations that run on the web in the Adobe Flash Player. Flare applications can be built using the free Adobe Flex SDK or Adobe's Flex Builder IDE.