I wanted to learn a little bit about mapping software–GIS systems, and someone suggested I read a book called How to Lie with Maps first. I haven’t gotten around to learning the software yet, but I did read the book.
The main point of the book is about how to look at data critically, and understand the assumptions that go along with it. Maps can show information clearly and concisely, but they can also mislead. Sometimes maps can create an illusion that weak information is much better than it is.
I have been looking at information related to pesticide use in the U. S. There are a lot of opportunities to examine the assumptions used and the data quality of that information. The intent, I assume, is not to lie. The information that is reported, however, is a big lie.
For example water departments analyze a list of about fifty organic chemicals, a good percentage of which are pesticides. They report that data annually to their customers as a “consumer confidence report.” But of those pesticides, many have been outlawed and are no longer manufactured. Many pesticides that are currently in use are not analyzed for. The illusion is created that concentrations of pesticides in the environment are known. Not true. We are measuring the wrong thing.
There are other instances of too little information being compiled into official-looking maps. I will show some examples when I get a little more time.