One of the first things I learned studying abstract mathematics was that having non-examples were as important as examples of abstract structure. For instance, the definition of a group and some examples of groups it really only part of the picture - having examples of sets that satisfy all but one of the requirements to be a group allows you to see how the pieces fit together and lays a foundation for more solid intuition for further study.
Every time there’s news about a mass shooting I feel like doing some type of data analysis about gun violence. With the shootings in Dayton and El Paso, as well as news of several likely shootings being prevented, I thought I would actually follow through with some analysis. Having been a senior in high school (in California) when the Columbine shooting took place, and also living in Salt Lake during the Trolley Square shooting I’ve seen the impacts of these tragedies and feel as though they are happening more frequently.