Ah yes, more slight of hand. In this instance, you have moved the goalposts to "mass" school shootings, only counting instances where 4 or more people were killed/injured. This list also doesn't seem to include shootings that took place at colleges, which are also schools (Virginia Tech, Northern Illinois and Umpqua come to mind). It almost like you don't question your source at all and just happily accepted it because it fits your bias.
Even if we just focus on K-12, you could download this [1] data from US Naval Postgraduate School and run a trend line all the way back to 1970.
Yes, perhaps the study I linked to that from Northwestern using FBI Unified crime report sources, and a published data set you can examine - is biased and wrong.
While your source that has no data at all - that does seem more trust worthy. Not to mention rate vs incidents.
Your source was a news article from Northeastern, not Northwestern, about a study. That said, the study's data source is cited in the article as: "Fridel and Fox used data collected by USA Today, the FBI’s Supplementary Homicide Report, Congressional Research Service, Gun Violence Archive, Stanford Geospatial Center and Stanford Libraries, Mother Jones, Everytown for Gun Safety, and a NYPD report on active shooters."
The source I provided is literally only data, with no editorializing. It comes from this source: "The School Shooting Database Project is conducted as part of the Advanced Thinking in Homeland Security (HSx) program at the Naval Postgraduate School’s Center for Homeland Defense and Security (CHDS)."[1] It also has a publicized data set you can examine.[2]
You are not biased at all, but anyone who dares disagree with you must be.
"The (K12SSD) table at right shows that the majority of “school shootings” over the last 48 years occur outside while on school campus. When tied in with non-shooting “school shooting” definitions, such as brandishing, we get a very different picture. By this project’s definitions, if someone on the sidewalk outside the school brandished a gun, that was a “school shooting”. Three percent of “school shootings” in the database involve no shots being fired at all. And if we include single shots (regardless of from where they came, or if they were suicides, or if they were late at night, etc.) those add up to 63% of all incidents."
==I hardly think K12SSD's releases come "with no editorializing". ==
We could have a long discussion about what should and shouldn't be included in the data set. Should a bullet that hits a school building be counted? Should brandishing count? Should we only count incidents where people die? Does there need to be 4 or more injured? etc.,
The comment about editorializing was in reference to how one source was a news article interpreting a data set (the definition of a narrative) and the other was simply a data set.
Even if we just focus on K-12, you could download this [1] data from US Naval Postgraduate School and run a trend line all the way back to 1970.
[1] https://www.chds.us/ssdb/number-killed-by-year/