Why make visualizations?

Yesterday you looked at a bunch of data from the Pew Research Center that was all presented visually in graphs and charts. The question is: why? Why did they choose to make a bunch of charts and graphs rather than just showing the raw data itself?

• “Why did Pew Research choose to make a bunch of charts and graphs rather than just showing the raw data itself?“
• “List a few advantages and disadvantages (at least 2 for each) of using visualizations to communicate data”

Google Flu Trends

Read on of the following articles and answer the following question:
“Why did Google Flu Trends eventually fail? What assumptions did they make about their data or their model that ultimately proved not to be true?“

Wired - What Can We Learn from the Epic Failure of Google Flu Trends?
NYTimes - Google Flu Trends: The Limits of Big Data
Nature - When Google got flu wrong
Time - Google’s Flu Project Shows the Failings of Big Data
Harvard Business Review - Google Flu Trends’ Failure Shows Good Data > Big Data

Trends

Last week we started to collect data about ourselves so that we could learn about trends and patterns in our behavior. What is meant by the term "trending"?

Data Collection

Data is all around us. What are some examples of data and give a couple specific reasons as to why someone would collect data.

Intro to Data

The last project you did (Encoding an Experience) was about organizing and structuring digital data to represent complex information. You did it by thinking about bits. In reality we typically don’t have to break digital data down all the way to bits in order to work with it, but understanding that digital data at its root is just bits gives you insights into working with larger data sets. We are about to embark on a new series of lessons where you will work with real data sets and learn how to use to tools to explore and extract information and knowledge from the data. 

But before we do that, what exactly is data? Explain in your own words.

Encode an Experience.

We have come to the end of another unit where we have been building layers of encodings on top of the foundation of bits.


First we learned to develop binary numbers, then ASCII text, then formatted text, and finally color images. High-level encodings are actually quite removed from the underlying bits from which they are made.

What does it mean to encode something?

When we use the term abstraction, what are we referring to?

Lossy Compression

You have been experimenting with how images and files are compressed on a computer and how in turn those files are encoded by the computer. 

• With a partner, go to the Lossy Text Compression App. (Unit 2: Lesson 5)
• Answer the following questions:
• What is happening in the app?
• Should this “count” as text compression?  Why or why not?
• What do you think “lossy” refers to?

Limitations to RGB

Over the last couple of lessons we have been experimenting with RGB color palettes to create different shades of colors while varying the bit sizes of each color. When creating colors on the computer using the pixelation tool, changing the bit size does what? If I wanted to make an image lighter or darker how would you alter the RGB settings? Are there limitations on how light or dark you can go?

RGB Color Model

When we mix RGB colors what are we really doing?

How is mixing paints in real life different than when we mix the colors on the computer using light?
Example: Provided you have a white canvas:
To make white?
To make black?
When you mix red and blue?

Encoding Colored Images

In the previous lesson we came up with a simple encoding scheme for B&W images. What if we wanted to have color?

• Devise an encoding scheme for color in an image file.  How would you represent color for each pixel?  
• How many different colors could you represent?
• Do you have a particular order to the colors?

Encoding Images

Please answer the following:

(K)now: Do you already know something about how images might be encoded?

(W)ant-to-Know:  What would you like to know? What are you wondering about?

Compression Rate

For the last day or so you have been working in Code Studio compressing chunks of text to the achieve the best compression rate possible. Let us test your knowledge.

 

What is the compression rate, or the compressed text size + dictionary size compared to the original text size. (as a percentage)

Is this a “good” compression rate? Why or Why not?

Lossy and Lossless Compression

Compression allows Internet users sending large files to reduce the overall bits and bytes in a file so that it can be transmitted faster over slower internet connections or take up less space on a disk. We have to different types of compression methods, Lossy and Lossless compression. Explain in your own words the difference between these two methods.

Text Abbreviations

When we are texting or sending messages to our friends, many times we never completely type out every single word.


What are some abbreviations for words when sending messages?


Write some examples of things you might see in a text message that are not proper English.


Why do you use these abbreviations?