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Project 4 – Tree Visualization

Group members: Lyla Medeiros and Jae Vick

The group held an initial brainstorming session in which they decided to visualize the

classification of major dinosaur families. The data for the classification came from the website

http://www.enchantedlearning.com/subjects/dinosaurs/dinoclassification/Classification.html One

of the things the group liked about the data was that it did not need to be cleaned. The

presentation of the data was straightforward and would only need to be transferred into a

different format. When assessing the original Dinosaur Family Classification on the Enchanted

Learning website, the group identified the strengths as: legibility/ easily readable font, simple

structure/ intuitive to follow, appropriate amount of information. The group identified the main

weaknesses of the presentation as: lacking artistic appeal as well as an inability for the viewer to

get a broad sense of the classifications due to the need to scroll up and down the page while

viewing the groupings and reading the text from left to right.

Design Process

The group came up with three initial ideas to create the tree visualization based on the dinosaur

classification. The designs are listed in order of implement ability (purely conceptual to workable

with the tools we can manipulate).

1) A 3-D holographic tree in which each node would consist of the name of the family

and a representation of the biological factor that created the split from the previous family. For

example, the node representing the Ornithischians order would show the most typical example of

a bird-hipped dinosaur joint. The edges of the tree would be represented by the transformation of

the image into the next evolutionary change, creating a 3-D display that would engage viewers

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beyond the names and facts, to show the biological differences that make up the order and genera

of dinosaurs.

2) The group thought it would be interesting from an artistic standpoint to use the edges

of the tree to create the shape of a dinosaur. For example, the order, sub-order, infra-order and

family could be molded into a representation of one of the genre. The group decided that this

would be interesting but not useful someone who was interested in the data for reference

purposes.

3) Working under the idea that it was important to retain some of the simplicity and

intuitiveness of the data set, as well as rely on pre determined mental models of a tree

representing a biological classification scheme, the group decided to construct a tree that would

read vertically, which would eliminate the uncomfortable situation created in the original

(scrolling vertically but reading horizontally). The group decided that creating an interactive tree

would enable us to represent each genera with at least a picture when the user hovered on the last

node representing the family. A sketch was made and sent to an expert user, a biologist, for

comments.

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User survey comments:

1) “Do the branch lengths mean anything? In phylogenetic trees they usually represent

the time in between an ancestor and its descendants”

2) “Considering my first comment, I don't really like the way the time periods are

represented perpendicular to the tree, they should be in the same plane as the tree,

since the tree moves forward in time. maybe if you place the timeline moving in the

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same direction as the tree that would make more sense!”

3) “Why are most species placed at the junction of two lines but two are placed along the

line (e.g. ornithopods)?”

4) “Do all these things end up extinct, or do some of them have surviving descendants in

modern times? like, some dinosaurs became the birds, some became the reptiles, are

any of those groups represented here?”

5) “This comment is on the pop-out thingy that I got in the second email - is this internet

based so that when you scroll over a name it gives you a picture and more info? If so

that's cool and gives users a chance to pick the level of detail they want to see.”

We tried to address the length problems expressed by our first interviewee on paper, but found

that there were significant space and labeling issues. We also wanted to use pictures of the

dinosaurs, and were very concerned about being able to do so in the space we could find on

paper if all the lines were the same length, and we indicated time in the way she had asked. First,

we decided that because we were using all dinosaurs that lived in the Cretaceous, it was

necessary only to label them as such, and not to include a dimension of time. This was good for

two reasons: first, we are showing a classification scheme, and not an evolutionary hierarchy,

which means that time is not, strictly speaking, a variable; second, . At first, we couldn’t think of

how to do this without making it interactive. Then, it occurred to us that we could make it

interactive without making it digital, and solve the space problem all at once, if we made it three-

dimensional. We decided to create a mobile, sketched below.

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Initial weighted model

Color-coded model and detailed card sketch

Initial model for card and wire configuration

Initial sketch of possible branch design, rejected in favor of equal length lines

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Our second interviewee is an amateur dinosaur enthusiast.

Concerns:

1. What  specific  organizational  system  are  you  going  to  use?  There  are  a  few  that  are  

in  use  in  the  paleontology  community.  Make  sure  you  are  not  mixing  them.    

2. I  am  worried  about  the  physics  of  this.  You  may  have  to  weight  it  or  add  structural  

supports.    

3. I  like  the  information  you  have  on  those  cards.  Maybe  include  that  information  

about  the  other  levels  of  organization?  At  least  the  name  of  the  level  and  the  

meaning  of  the  Latin,  I  think  you  should  include.    

4. I  think    it’s  a  really  good  idea  to  have  all  the  same  level  of  organization  on  the  same  

level  in  the  representation.  You  don’t  want  to  make  any  value  judgments  about  some  

things  being  better  or  worse,  greater  or  lesser,  more  or  less  evolved.  They  all  exist  at  

the  same  time,  so  they  should  all  be  at  the  same  level.    

We definitely took to heart our second interviewee’s concerns about the system, and went back

to check to make sure that all items on each level were also on the same level in the source

classification scheme, and then made sure that in the realization of the mobile, they were labeled

clearly. We also made sure that in later sketches and in the realization of the mobile, weights

were added. At first we imagined adding rocks and tying them on with string. After looking at

some art mobiles, however, we decided to use a large loop of wire. Many of the structures that

result are quite organic, and beast like. They especially remind me of the ceratopsia. If we had

much more time, we would prefer also to make this out of much thinner thread. Many mobiles

are made with invisible fishing line, but as the vertical lines of twine represent the connection

between each larger classification and its sub-class.

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Resketch based on feedback:

Although we are excited about the mobile and think it was a good solution to our level problem,

it would be an even better model to use for a tree with many branching levels and relatively few

items at the bottom of each branch, as seen in this image of one of Calder’s mobiles, which looks

very similar to a cladogram.

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We also wish we could have incorporated color as a classification mechanism, rather than just

for the dinosaur illustrations, as in part three of our mobile sketch, but in the short time we had

available, we were not able to realize this. One element of the mobile that we really like is that,

being 3-D, it has many possible views that are easy to access and interact with. It seems silly to

talk about the advantages of physical space, but we feel that this is an important point about our

choice; because we have chosen to make an information visualization that is not accessible in its

full-featured form electronically or remotely, it is important to detail the advantages that balance

out this significant disadvantage. It is easy for a viewer of our IV to view all the cards at once,

but also to view the whole without distortion or zooming issues. If the viewer wishes to

understand better the connections, she could physically trace the lines. “Zooming” or “hover” in

our case is simply moving closer to the mobile, and reaching out to touch or hold one of the

cards, or bring it closer to the viewer’s face. One disadvantage is that our prototype quickly

ballooned in size because of the size that the cards were required to be for the detail of the

images and legibility of the text. If this is something a client (for example, a museum) was

interested in pursuing, mobiles are regularly made to be extremely large. Below is an image of

one of Calder’s mobiles:

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For comparison, here is the size of one of the exhibits at the American Museum of Natural

History in New York City.

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A mobile of this

size would be at

least as ambitious as our first idea about an interactive way of doing this that also traced the lines

of the body of a dinosaur, it incorporates some of the same ideas and is radically low tech.