CHAP TER 1 Introduction Have you ever wondered how to read a confusing map Or maybe you saw an odd picture on your Instagram timeline It was not a picture of a pet food or sunset Instead it was filled with numbers and words and you didn’t know where to start These kinds of images are called infographics If you have seen images like this and wondered what they meant this book is for you Maps infographics charts and other things that show information visually are called data visualizations Data visualizations are everywhere They are shared on social media presented by politicians and journalists and hung on classroom walls Even a subway map is a kind of data visualization 4 21st century skills library
If you’ve ever used a map to find your way you’ve successfully read a data visualization Because data visualizations are so popular we need to know how to read them Data visualizations can be fun For example they can tell you the most popular bands in different states who cooks the weirdest food on Thanksgiving and where people like to travel to the most in winter Many other kinds of important information are contained in visualizations as well You might look up directions or weather forecasts using maps You might look at charts to learn about crime statistics This book will break down data visualizations and explore what different types do well and not so well This way you can easily read confusing data visualizations 5 55 Data Geek
What data is visualized on this map London’s many underground and aboveground public transportation systems Using colors and special symbols in place of each station and traffic helps us see the system quickly Subway Maps Believe it or not subways existed for years before anyone made maps for them The first subway was the London Underground which opened in 1863 Each train line in the subway system was owned by a different company and no one wanted to make maps of anyone else’s lines A newspaper called The Evening News created the first map to show all the lines in 1907 All of these maps tried to show the lines geographically That means they tried to draw the train lines exactly where they would be in the city This made it very difficult to show the entire network It wasn’t until 1931 that Harry Beck created the first diagrammatic map of the Underground It only shows the order of the stops on the train lines and where they meet This is the kind of map still used for most subways today 6 6 21st century skills library
CHAP TER 2 Pie Charts The first kinds of visualizations we will talk about are pie charts Despite the name most pie charts don’t contain any information about pie They are called pie charts because they are round and cut into slices They are sometimes also called circle charts This chapter will slice into what pie charts are used for then bake up some elements to look for when you read a pie chart Pie charts are best used to compare parts of a whole Let’s say we have a pumpkin pie If we cut it into six equal pieces each piece is one-sixth 17 of the pie If we made a chart showing those six pieces it would have six equal parts Some pie charts have pieces of equal size but most do not Pie charts are also good for comparing fractions of different sizes that are part of the same whole Let’s look at an example Data Geek 777
