Cohesion, or how well your question fits together, is closely related to scope, or the ground that your question covers. Every question has two attributes that determine its scope: the assigned subdistribution (e.g. American History) and your question's theme. You can think of a theme as the hidden "thesis statement" of a question: what is it trying to say? And you can think of cohesion as a measure of how compelling the theme is. Often, a theme is as simple as an answerline paired with its subdistribution (e.g. George Washington in the context of American History). But the best questions have more specific themes. Consider the following tossup:

In this case, the theme is much more specific: speeches by and about George Washington in the context of American History. This is a good example of how you can have a specific theme while keeping your answerline broad. It is also good use of answerline calibration: it is easier to write than a tossup on "George Washington's speeches" would be, even though the same clues would work for both. When in doubt, keep things simple!

When I say "narrow scope" and "wide scope", I am mostly speaking in terms of hierarchies. A lot of the quizbowl canon is hierarchical. Let's use the Literature Canon as an example. Characters are in books. Books are written by authors. Authors are from countries. A tossup on "Michael K" requires much more specific knowledge to answer (and is thus much more narrowly-scoped) than a tossup on "South Africa" that mentions J. M. Coetzee (widely-scoped). So a question with "narrow scope" is going to be "downstream" on the hierarchy: on the character end of things. Using answerline calibration (see previous) to navigate scope is a great way to control difficulty without changing the clues themselves.

But it also encourages lazy writing. Maybe you want to write a tossup on J. M. Coetzee, but you can't find enough clues. Darn, you think. But what if I just wrote a tossup on South Africa and filled the rest with Nadine Gordimer clues? Problem solved. This is a bad way to think about question writing! Whenever you go "upstream" in the hierarchy, you should have a reason for it. Maybe a tossup on Coetzee would be too hard on its own. Or maybe Coetzee is difficulty-appropriate, but the author you really want to focus on (say, Zakes Mda) is too difficult. In that case, asking about South Africa would be an accessible way to include the content you want. But Coetzee and Gordimer are both difficulty-appropriate for college, so this would just be needlessly widening the scope of your question (and weakening your theme).

However, there are many valid reasons to go upstream! Another reason you might want to go up the hierarchy is that you want to spotlight a certain theme that can't be captured downstream. In this forum post, Will Alston demonstrates why you might want to write a question on "Russia", where all the clues are about Jewish people. This is a more advanced example of answerline calibration: even though the question is about two commonalities, it is more straightforward to ask for just one.

At minimum, you want to make sure that your theme is fully inside of your subdistribution! So don't write an American History question on "George Washington's legacy" that clues the University of Washington football team. But in general, narrowly-scoped questions are more cohesive. This is because widely-scoped questions usually have weak themes. We can return to our thesis statement metaphor to understand this: an essay on the "American Revolution" in general is going to lack focus compared to an essay on "George Washington", which will in turn lack focus compared to an essay on "George Washington's speeches". Now a theme is obviously going to be less detailed than a thesis statement. But think about it this way: if you gave a talk on your theme, you wouldn't want your audience to be confused. On the other hand, make sure that you have enough clues for your question! In general, the concepts earlier in this guide should be prioritized over cohesion.

A statement that ties this all together is the Rule of Themes. The Rule of Themes states "the more areas of knowledge your question covers, the stronger your theme has to be". This is especially true for bonuses, which have more explicit themes. Here is a question that does NOT follow the Rule of Themes:

This question drifts from earth science to astronomy to physics to biology with no obvious theme in mind. The only thing that holds this question together is the word "lens", which is a tenuous connection at best. If you were to give a talk on "the word lens across many fields of science", your audience would be confused. Not to mention that your question probably isn't inside of the assigned subdistribution! You want to make sure that your target audience "stays with you" in the course of a tossup.

Note that nothing I have said so far covers how to find appropriate themes or what makes a clue interesting. This is something that varies by category, so you're better off talking to an expert! I'll talk about that and more in Part V: How to Get Started.