To take the measure of a person or a situation. Also: dip-stick.
In public, Secretary Powell, the four-star-general-turned-diplomat, has done what he always does: soldier on, shaping his commander's policies as best he can from within, with some success. In private, Secretary Powell, an amateur automotive mechanic, complains that old friends spend too much time sympathetically taking his temperature "dip-sticking me," as he puts it.
Todd S. Purdum, "Embattled, Scrutinized, Powell Soldiers On," The New York Times, July 25, 2002
What most educators mean by "doing Madeline Hunter" is using her seven-step approach to planning a lesson. In Santa Barbara, as in most of her road shows, several hours are devoted to spelling out this technique, which calls for specific acts of review, introduction, explanation, "modeling" (demonstrating), "dipsticking" (checking for understanding), "monitored practice" and independent study.
David L. Kirp, "The classroom according to Hunter," Los Angeles Times, August 12, 1990
The metaphor underlying today's word is the classic automotive oil check. Car engines contain a dipstick, a long, thin piece of metal that reaches down into the sump where the car's oil resides at rest. To check the oil, you remove the dipstick, wipe off the oil, and reinsert the dipstick as far as it will go. You then remove the dipstick once again. A bit of oil will cling to the end of the dipstick, where there are markings that indicate oil level. By comparing the oil to the markings you can determine if you need to add oil to the car.
So, since it seems to be the destiny of all nouns to eventually turn into verbs, dipstick has acquired today's meaning. (If you grew up in the sixties or seventies, then you probably know the slang meanings of dipstick, only one of which is suitable for a family publication such as this(!): a stupid or offensive person.)
Somewhat surprisingly, the verbing of dipstick occurred in the classroom. Teachers dipstick their children, which means asking questions about the current lesson as they go along. If the students consistently answer the questions correctly, then the teacher can assume that the lesson isn't going too fast or over the students' heads.
The earliest citation refers to this technique and hints that the term was coined by education theorist Madeline Hunter.