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Stretch Your Digital Dollar

Moving Beyond Bar Graphs with Data Visualization

April 26, 2010 · 2 Comments · Web 2.0

In essence, data visualization is simply creating graphs and charts. It’s taking data and displaying it in a way that’s meaningful for your audience. As teachers (specifically math and science teachers), we’re constantly teaching our students about data visualization. We want our kids to both be able to understand visualizations, as well as to create them.

But developments in technology have taken data visualization to an entirely new level. Researchers today are able to manipulate, analyze, and display data in formats I, for one, never dreamed of.

Take this visualization, for example:

from hint.fm

from hint.fm

The creators looked at photos of the Boston Common posted on Flickr, a photo-sharing site, for a full year. They then analyzed the presence of colors within the photos. The visualization shows the distribution of colors, by month (March is at the top). You can see that, in the winter months, the colors are mostly white, gray and black, but as you move around the circle, toward the spring, the variety of colors in Flickr photos increases. What an intriguing way to communicate this data.

In this TED talk, Hans Rosling uses impressive visualizations to communicate major ideas regarding global poverty and health:

Data visualization’s place in the classroom

Many teachers are already using one data visualization tool, though they may not realize it. Wordle is a FREE site that creates word clouds out of text resources, aligning the size of words with their frequency. Here’s a Wordle of all the text on my blog:

wordle
 
If you haven’t already used some form of word clouds in your classroom, you can see how they’d be helpful for students analyzing, for example, themes of a novel or a set of poems. Compare the information gathered from a word cloud with the information gathered if I used the same data to create a bar graph. With a word cloud, like most data visualizations, the audience can understand the information almost immediately because it is displayed in such a clear fashion. There isn’t as much of a need to decode the data or the graph.

LINCOLNUpdate: A new site, called Tagxedo, allows you to make word clouds in specific shapes, like hearts, doves, or even Abraham Lincoln. Users can upload a photo, and have their word cloud appear in that shape. The site is currently completely FREE, but some features will eventually carry a fee. (And, unlike Wordle, Tagxedo gives users the option to save or embed their word clouds, rather than forcing users to take a screenshot.)

In the world our students will inherit, there are more people alive than have ever been alive, collectively, in all of human history. And there’s more information accessible than has ever been accessible. These two facts can be extremely overwhelming.

To function in this world, then, our students are going to need several new 21st century skills – skills that we, as students, didn’t necessarily need or learn. One of these skills is the ability to clearly communicate ideas in a world of billions of voices. A second skill is to be able to analyze and utilize all that information quickly and easily.

Data visualization is a tool that teaches both of these skills extremely well. And it’s a technology that can be seamlessly integrated into what’s already happening in our classrooms, specifically in math, science, and social studies lessons. (Though, as Wordle illustrates, data visualizations are definitely cross-curricular tools.)

Not to mention that it’s an emerging field in which many of our students may one day find careers.

Creating Visualizations

When it comes to utilizing data visualization in the classroom, there are two major paths:

  1. Students can input their own data sets (either original data or publicly accessible data sets)
  2. Students can manipulate data that’s already been input into a visualization.

1. Inputting your own data

Many Eyes

Most science and math teachers have students collect their own data sets, both because it improves student understanding and because it tends to motivate students. When I taught middle-school science, my students created data sets almost weekly. A large part of classtime was dedicated to deciding what types of graphs would best illustrate the results and, then, to creating the graphs.

These experiences are definitely necessary for students but, by mid-year, nearly all of my students could create a line graph, though it would still take them hours to complete. And, of course, line graphs aren’t exactly the most exciting (or best) way to communicate data.

In retrospect, I think that, after I knew my students could create their own graphs, I would have turned them onto Many Eyes. Many Eyes is a FREE, simple-to-use data visualization site that allows users to display their data in any of about 20 ways, including word clouds.

I like Many Eyes because, though it’s easy to import data (you just copy and paste from any Excel or text file) and work through the visualization steps, it definitely takes some higher level thinking skills.

First, students have to decide what type of visualization will best display their data – a bubble chart, a line graph, a word tree, a block histogram, etc. Then, students have to ensure that their data is displayed properly, with the variables on the correct axis (if not, they can change them). So, while you get more impressive-looking graphs, your students still have a lot of difficult thinking to do.

In fact, by taking out the rote “this dot goes here” tasks, it’s easier to focus students on those higher-level analysis and evaluation skills.

Here’s a sample Many Eyes visualization, showing the number of layoffs in 2009 by industry (color) and company (dot) (click to interact):


 

One warning about Many Eyes: all the data you import becomes publicly accessible, so you’ll want to make sure students aren’t including, for example, classmates’ last names or personal information.

Google Gadgets

A lot of teachers already have their students use Microsoft Excel to analyze data. While this is a fairly good tool, most users will agree that it’s pretty boring and complex software, especially for younger students.

Google docs allows users to create spreadsheets in a format that’s very similar to Excel. But what I just discovered was an option under the “insert” menu to insert a gadget. Unlike regular charts and graphs, the gadgets available here can turn Excel data into pretty interesting visualizations.

In fact, Google bought the coding used to create the visualizations Hans Rosling used in the TED video embedded above. So it’s now possible – and fairly easy – to create a similar “motion chart” using your own data.

To create this type of chart, your data does need to be organized in a certain manner. Click here for step-by-step directions on using the motion chart gadget.

Finding data sets

As teachers, we all know the importance of having students collect and use their own data in class. However, there are times when our students simply can’t collect their own data, for example, when studying hard-to-reach areas like the deep sea. In those cases, there are a lot of public data sets that students can access.

In the past, I’ve shied away from these data sets because they’re extremely large and complex. It would be impossible to ask students to create their own hand-drawn graphs and charts. But with visualization tools like Many Eyes and Google Gadgets, students can finally work with these complex data sets meaningfully.

The White House has recently made tons of data easily available online. The United Kingdom has a similar site. For climate change and oceanography statistics, check out the National Oceanic and Atmospheric Administration.

2. Manipulating Exisiting Visualizations

In addition to creating their own visualizations, there are a couple of sites that allow sudents to manipulate charts that have already been created.

Gapminder, which is the visualization site Hans Rosling used in the video above, is FREE and open to the public. (There’s even a specific page for teachers that provides shortcuts to tools and guides for using Gapminder in a classroom.) Anyone can access global statistics about carbon dioxide emissions, education rates, poverty levels, etc.

Just as Mr. Rosling did in the video, users can choose which data they’d like to see on the x-axis and on the y-axis, so you can compare hundreds of global data sets and see how the statistics have changed over time. It really is remarkable (and, for dorks like me, be careful: you could easily while away hours on the site).

Using the Gapminder code, Google recently started its own data visualization site. The site is still in the test phase, but users can choose from dozens of public data sets to create visualizations. This video gives a brief run-down of how it works:

Data visualization isn’t just a tool for student projects, though. Teachers can create (or use) visualizations to help students understand complex concepts. I want to stress the importance of having students work with these visualization tools, in order to build their higher thinking and 21st century skills. However, I think most teachers will probably demo visualizations before and (given the time constraints of the classroom) probably more often than their students might utilize them.

Lesson Integration Ideas

Elementary Classrooms

Grade: K-5
Subject:
Math (or Science)
Objective:
The student will be able to explain and demonstrate how things change over time.

With younger students, I think it’s important that they still create their own charts and graphs by hand. But visualization tools can allow teachers to take students a little further into data analysis.

As a 4th-grade teacher, I always taught a math unit called “Changes Over Time.” As part of the unit, students grew small plants and collected data for graph creation. Students started by each planting their own seed in a small paper cup (or re-used milk carton) filled with soil and labeled with the plant’s name (I had students name their plants).

Every day, students would record the overall height of their plant, the number of leaves, and the date. After about a month, each student would make a simple graph demonstrating how their plant’s height changed over time.

With the Google Motion Chart Gadget, though, I could have taken this lesson a lot farther. Students could have shared their data and then compared how the entire class’s plants grew.

To create a visualization, a teacher could create a Google spreadsheet document and label the columns as follows: The “A” column should be the plants’ or students’ names. The “B” column should list the dates that you recorded data. Then label a column for each of the remaining variables – plant height and number of leaves. Depending on your students’ level and your equipment availability, here are some ideas for how you could create a class-wide data visualization:

  • share the Google spreadsheet, and have students open it individually to add their data
  • project the Google spreadsheet on the board, and call students up to enter their data, one by one (after the first few students, you might want to have the class start working independently on an activity, such as creating their hand-drawn graphs, as students enter their data because it will take a while)
  • project the Google spreadsheet on the board, and have students read their data aloud as the teacher enters the data (again, you may want to have students working independently after the first few students model what to do)
  • have each student (or student group) create their own Google spreadsheet; the teacher creates one as well, and projects it on the board; the teacher enters all students’ data into his/her spreadsheet as a model; and students copy all students’ data into their individual spreadsheets

Once all the data is entered, click insert > gadget > motion chart to create the playable graph that will show students’ named (and colored) dots moving as time passes. You can use the chart to start a conversation about how the variables are connected, how the plants changed over time, and how different students’ plants compared to one another at different times. (When played, students will likely see the visualization as a race, watching their dot overtake or fall behind their classmates’.)

Middle School Classrooms

Grade: 6-8
Subject:
Science
Objective: The student will be able to communicate the results of an experiment.

Throughout the school year, middle school students complete dozens of lab experiments, and they often collect unique data sets. Once you’re confident that students are able to create their own basic graphs, have them use Many Eyes. Students can type or paste their data directly into the site, assess 20 visualizations to find the one that will best communicate their findings, and create a visualization with two or more variables. Not only will the product help students communicate their findings, it may help them make discoveries about their data that they didn’t recognize earlier.

High School Classrooms

Grade: 9-12
Subject:
Social Studies (World History and Economics)
Objective:
The student will be able to explain how socio-economic stratification affects human motivation and cultural values.

Gapminder is an amazing tool. It’s pre-programmed with hundreds of global data sets. All students have to do is choose the variables they’d like to compare and press the “play” button.

Often, it’s difficult for students to understand how socio-economic status and stratification affects other aspects of life. But with gapminder, they can have the x-axis display the GDP (income per person) of various countries, and change the y-axis data to see how they compare. Is there a correlation between health and wealth? HIV infection and wealth? Education and wealth? Infant mortality and wealth?

After working with gapminder for a class period, students can choose a research paper topic related to some of the data they saw. Using the data as a starting point, students can flesh out a thesis and a paper related to wealth’s impact on a variety of other factors.

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