indigo_rose99

It turns out that school shootings have been happening for a much longer time than I had any idea.

People keep talking about "The number of school shootings this year is..." and then they will name a number that just seems insane. So I went looking for a reference and some data. Wikipedia is our friend. Without too much trouble, I even pulled the data into some statistical software and started making graphs to answer my curious questions.

How many deaths and injuries have there been in school shootings? United States only. Each point in the following graph is an incident. There is a red and blue point for each shooting incident -- red x for deaths, blue point for injuries.


Yes, there was one in the 1700s. Cray. 



Everyone keeps talking about how the number of shooting incidents is going up. Is it? I mean, it kinda looked like the points in the above graph were becoming more dense as we move toward the present. What if I summarize the data by year? Are recent years getting worse? Each point in the graph below is a year. The top black points are the number of shooting incidents in that year. The bottom graph is the deaths and injuries that year.


When looking at the above graph, when did the number of incidents start taking a turn upward? In a no-statistics-tests way I played with the graph and it looks like it happened sometime in the 1960s.

How does this year (2018) compare to past years? It seems a bit unfair to strictly compare ALL of the data in past years to just this point in 2018, so I made a subset of the data that made the above graph to include only incidents that happened up to this point in the year.



And the same graph, with 2018 highlighted.



To me, it looks like at least one past year had more incidents up to this point. But 2018 has had more deaths, more injuries when compared to previous years up to this day of the year.

More information and better graphs does not make this any less depressing.

I am watching Gore's film on the Discovery Channel.  I have to admire his amazingly good use of graphs!  Every graph is simple, clearly labeled and fits perfectly into his talk.  Even when he puts two graphs on top of each other, it is obvious which y-axis goes to which line.   Each graph builds on the information discussed in the previous graphs.  He talks about trends and outliers.  He puts graphs about the last 20 years into the context of millions of years of variation.  He keeps to his message and uses only graphs that do not muddle his point.

Wow.

I aspire for my students to use graphs HALF this well.