As I make adjustments to curriculum for students here at HoneyFern, this question keeps coming up for me. For the record, not once has my response included anything along the lines of "does well on standardized tests." Let's get that quickly out of the way.
Educated people ask questions and find answers. When they find answers, they are able to think about what they find and ascertain whether or not the source is reliable. They know what to do if there is contradictory evidence, or if bias is obvious but irrelevant. Educated people form opinions based on information and their own internal compass; they listen to other people, whether they agree or not, and they don't feel the need to convert, conform or confront just for the sake of doing so.
Educated people have a baseline of knowledge, but it is hard to define what exactly should be included in this baseline. This is what public schools and standards have tried to achieve (and, I might add, failed to an extraordinary degree). I am still working on how one decides what is essential, but I am pretty sure no one has gotten it 100% right yet.
Educated people are intellectually curious; they have conversations that go beyond the mundane, and they cultivate ideas. Educated people can communicate their ideas effectively, both verbally and in writing. There is no getting around this. They do not need to use the pedantic grammar verbiage (as required by 101 college classes), but they need to understand that how they say something, and in what order, influences the effectiveness of their communication.
Educated people need to know how to make decisions. They need to know when they are wrong, and how to fix their mistakes.
How do I write curriculum to develop an educated person? This is no small task. Reading, writing and experiences lead the pack for me; these develop a broad knowledge base and help students find what they are passionate about. I like to ask lots of questions so students have to think, and I don't care if they "know" the answer; I am much more interested in what they "think." I think I need to encourage a bit of supported discomfort; it seems to me that things have been too comfortable for too long, and this doesn't promote responsible risk-taking or intellectual expansion. At the same time, students won't take risks if they don't feel they will be safe in doing so; this is where relationship-building comes in, and I think HoneyFern does this well (if I do say so myself!).
This is just the beginning of the process for me; I want our work to be joyful and profound, and how this happens will take more time to flesh out.