The AP CS Principles curriculum is divided into five Big Ideas. In this unit, we will quickly cover the material under the heading Data. We already did most of this in unit 1 so that's why this unit is so short. Here are some links that we will use in this unit:

How Digital Audio Works. This 12 minutes video gets into sampling rate and bit depth is describing how analog signals are converted into digital a format.

How Image Compression Works. This video is not quite 7 minutes long and he gives a very good, concise over-view of how image compression works. I do not expect you to understand all of what he is saying but you should get the general idea of the process.

Data Compression video from Code.org We will do lessons 9 and 10 in unit 1 of their CS Principles course.

Google Trends This is an interesting site that lets you do explore trends in what topics are searched for. These can be filter by time, geography, and other criteria.

AP Classroom The site contains useful videos and sample questions.

Spurious Correlations This site has lots of interesting graphs that show how two totally unrelated trends can be highly correlated over some period of time. This is great way to illustrated the fact that correlation does not imply causation.