Arguably one of the more difficult aspects in teaching for understanding is to decide when to teach the desired understanding! In other words, to put it as an essential pedagogical question: When should you state the Understanding and when should you engineer students to come up with it  “by design”?  Whether we consider the famous example of Socrates in his Dialogues or some of the best teachers we have ever had as students, many of them had the ability to help us “discover” the understanding on the basis of their clever design groundwork, their probing, and their facilitation of discussion.
If Essential Questions frame ongoing and important inquiries about the issues and challenges in a subject, Understandings reflect important answers that derive from inference that we want our students to eventually “see” after seriously considering the questions.  Here’s an example: The essential question, “Why is that there?”, sets up a serious and ongoing inquiry into a big idea (a very general and powerful understanding – a theory) that perhaps “geography is destiny.”  As a result of exploring the question and related idea, we want students to come to specific understandings such as:

• Human needs for food, work, commerce and transportation often determine where people settle and cities grow.
• The geography, climate and natural resources of a region influence how people live and work there.

Notice that these specific understandings are not limited to a particular region or city. They are transferable across time and location in ways that facts are not. And if we do our job right as designers of focused activity and facilitators of discussion of implications, we can actually get students to “see” the understanding “by design” for themselves.
In other words, one of the great teacher misunderstandings is that we have to teach the understanding for understanding to occur. On the contrary, as mystery stories, movies, and (especially) video games reveal, the learner is not only perfectly capable of drawing appropriate inferences, such activity is key to increasing intellectual engagement and reducing the boredom of schooling.  And ironically, the literature on student misconception reveals that in spite of clear “teaching” of big ideas, many students do not understand what they have been taught (even if they pass our quizzes).
That said, we are not advocating for a one-size-fits all approach to instruction by calling for unending discovery. On the contrary, we have all had experiences in the other direction. Sometimes we point to and say the same thing, over and over – and only on the umpteenth time does the learner say – “Oh, I see! So THAT’S what you meant!”  Note the language: just because you said it a bunch of times doesn’t mean that they “see” what you mean.
An understanding has to be “seen” by the learners themselves; it has to be an “insight” that they “grasp” (or verify) with our assistance. Naïve teachers, by definition, think that understanding is transmitted like factual knowledge – as if it were obvious on first hearing (when in fact an understanding is an unobvious conclusion to novices). When you feel yourself getting frustrated as a teacher and either thinking or saying “Don’t you see this???” you can bet that you have not laid sufficient ground and facilitated enough dialogue and inquiry to put students in a position to get it.
Here are some tips for aiming at student ownership of Understandings:

1. Focus on a small number of Understandings per unit  (1-4). Since the Understanding(s) serve, in effect, as the “moral” of the unit “story” there simply cannot be too many for the experience to be coherent since you have to build inquiry and discussion toward those (not so obvious) conclusions. Initially in your teaching you may want to practice aiming only for 1 Understanding per unit to get a feel for the kind of groundwork and probing that needs to be laid for the Understanding to occur in students “by design”.
2. An Understanding is an inference, not a fact. This meta-lesson about teaching and learning for understanding must be made clear to learners throughout your teaching because most students think that the point of learning is to “take in” and “give back” the unambiguous facts presented by teacher and text. Take a page from the work of Taffy Raphael and others in reading (QAR), and signal early and often to students (until they really get the distinction!) that some answers are found “on the page” and others are found “in your head”. For example, Socratic Seminars and Problem-Based Learning are instructional approaches designed so that the learner must construct meaning, not wait for the teacher to simply “tell” the answers.
3. Before teaching the unit decide if the Understanding(s) will be helped or compromised by being stated or posted early on. There is no hard and fast principle on this point; it is usually determined on a case-by-case basis. Nonetheless, here’s a helpful rule of thumb: ask yourself if the Understanding, as phrased, will likely be completely meaningless or seemingly unhelpful until the students “see” its meaning. If so, you lose little by stating and repeating it, and you will likely gain quicker understanding. However, if in stating the Understanding you would completely undermine the inquiry, discussion, and testing of ideas needed to really have them earn their insight and “get it” then you probably should not state the Understanding until the “teachable moment” where it serves as a concise summary of what students have come to see or just said. Then, if others didn’t follow the inference you can now take them (or have students take them) through the logic that leads to the generalization.
4. Since an Understanding is typically a fairly general or abstract inference, encourage students to keep notes or use helpful graphic organizers of the facts, experiences, and claims that build toward their understanding. For example, graphic organizers can help student “construct meaning” from a collection of facts and textual information.
5. Since an Understanding is a fallible inference, it is important to strengthen student understanding by considering alternative understandings (including seductive misunderstandings) if you want the Understanding to really “take” in the students’ minds. We know from the research on concept attainment, that understanding demands looking at multiple, contrasting cases/examples/claims whenever there is an abstract idea to learn. That’s why debates ­– where students are required to consider counter-examples and counter-arguments – are often very effective (as well as engaging) in causing deeper understanding. You can build multiple and differing points of view into scenarios in both instruction and via GRASPS in assessments.