The word "compendious" indicates something is what?

The word "compendious" refers to something that is concise yet comprehensively covers the subject matter. It suggests that information is presented in a succinct manner while still conveying the essential details required for understanding. This quality makes it ideal for summaries or condensed versions of larger texts that encapsulate the main ideas without unnecessary fluff.

In contrast, vague and confusing materials (the first choice) lack clarity and precise details, resulting in poor comprehension. Lengthy and detailed content (the second choice) implies a thorough elaboration that goes beyond brevity, missing the hallmark of being concise. Lastly, overly complicated content (the fourth choice) often involves excessive complexity, which runs counter to the notion of being straightforward and easy to grasp. Thus, "compendious" successfully embodies the idea of being brief yet comprehensive, making it the most fitting choice.