Although I majored in government, I didn't take a single introductory-level government course during my four years at Cornell. Was this a mistake? Consider the following passage: If, like me, you're familiar with baseball, these sentences are easy to understand. It's a 6-4-3 double play. I can visualize this play in my head, since I've seen the same situation many times on television. If, however, you don't know much about baseball, it might take you a few readings before you have a good handle on what you've read. You can still get to the point of understanding, but it was a lot more difficult for you. As a history teacher in the inner city, I run into similar situations pretty often. Students have trouble using critical thinking skills to explore significant themes of history because they lack the necessary background knowledge. If my students don't know the two oceans that border the United States, or know that World War II took place in the twentieth century, can they really be expected to make higher-level conjectures about isolationism or naval strategy? I know a lot more than my students do, but I faced similar issues in a couple of my 300- and 400-level courses at Cornell. By jumping directly into upper-level classes, I missed some of the foundational material that would have made those classes easier. (An example: I entered my 400-level seminar on Islamic politics without knowing the difference between Sunni and Shia Muslims.) As a responsible student, I would do some searching on Google or Wikipedia to fill in the gaps in my knowledge. But it wouldn't have been such a bad thing if I had to repeat some of the intro-level material that I supposedly gained from my AP-level classes. Undergraduates in the liberal arts at Cornell are often eager to jump into higher-level classes: these courses meet less often, have fewer students, and offer higher median grades. But as I find out more about how students learn, I become more convinced that departments should mandate that students take at least two intro-level classes. Or, at least demonstrate a high level of mastery on an entrance exam. Foreign language departments already do something similar.Ashburn hit a ground ball to Wirtz, the shortstop, who threw it to Dark, the second baseman. Dark stepped on the bag, forcing out Cremin, who was running from first, and threw it to Anderson, the first baseman. Ashburn failed to beat the throw.