CS465 - Assignment Two

Due: 2014-02-27 11:00a

Objectives

• Get more practice making visualizations with R
• Start recognizing the various kinds of data
• Think about how the principles of perception apply to visualization

[45 points] Looking at visualizations

1. [5 points] Take a look at the iris data set that is included in R. For each of the attributes in the dataset, say if it is dependent or independent, interval, ratio, nominal, or ordinal, and continuous or discrete.

2. [5 points] Provide the lines of R that are necessary to produce this graph:

1. [5 points] Which Gestalt principles are we using to interpret this graph?

Now, we are going to look at the current Green 500 list. The Green 500 list is a ranking of the most energy efficient supercomputers in the world. Unlike the Top 500 Supercomputers list, the computers that are highly ranked in the Green 500 are not just fast, they are also energy efficient. Start by grabbing the local copy of the current list.

1. [13 points] Repeat question 1, identifying each of the attributes in this data set.

2. [12 points] Provide the lines of R necessary to produce the following graph. You may need to do some research to get this. I’ve specifically used some features that we did not use in class. I want you to gain (more) experience finding things out on your own. You should pay close attention to what I’m showing you so that you can break down the original data in a reasonable way. (I’ll give you a hint that I created a manual set of colors and the three colors I used were “green3”, “dodgerblue3”, and “lightgrey”)

1. [5 points] Visit the New York Times visualization of science exam performances. Look over the visualization. Make sure to mouse over the visualization and walk through the explanatory text in the upper right. What preattentive cues are they providing and how are they using them? What Gestalt principles are at work here?

Turning in your work

Use whatever tool you feel the most comfortable with to write up solutions to these problems. However, you must convert the document to PDF before turning it in. Name the file username-hw2.pdf, where username is replaced with your username (the Middlebury username that you log into the lab computers with).

I would like this document turned in in the DROPBOX on MiddFiles. You can refer to the reference on the LIS wiki to help you connect to the file server.