Do you know anything about music--or specifically, music notation? Even if you don't, you may be able to answer this question. Here's a note on a musical staff. Do you know what note this is?
Wait, don't answer yet! Here's a illustration of which note goes where on a staff with a treble clef, as we have here:
Okay, so what note is in that first picture? It's a D, right? I mean, it says it's a D right there on the picture, and then the chart on the bottom confirms that the second line from the top is, indeed, a D on the treble clef.
But I have recently discovered that this note, in a certain context, is not actually a D at all. Let me expand that original picture to give you that context:
Some of you may be nodding your head in comprehension now, but for everyone else, let me lay it out. Those open and filled-in circles at the bottom, along with the small T, are indicating which valves to press on the French horn to play this note. So what difference does that make? Well, it turns out that French horn music is notated a perfect fifth above the actual note. That means that when the music indicates you play this "D," the actual note is this G, a fifth lower:
I discovered this fact in the course of helping my daughter, who has taken up the French horn in middle-school band. But I only just discovered this fact this week, at the end of the first term, after weeks of trying to help my daughter hit notes well above her expected range.
It turns out that most brass instruments are notated differently than the actual "concert" pitch, and of course this is common knowledge to brass players--but not to beginning brass players, or their parents. But my daughter's French horn exercise book didn't tell me about this transposed notation, nor did her instructor tell her anything. The instrument itself is no help, because you can usually sound a note and the higher fifth using the same fingering.
So here's my point. I know a lot about music in general--notes, scales, keys, chords, and so on--but I know little to nothing about the French horn. My daughter has learned a good bit about how to play the French horn, but she knows very little about music in general. I tried to apply what I knew about music to help her, but I was missing one key piece of information. Without that information, everything I was telling her was off-kilter. I even bought her a contact tuner so we would know exactly what note she was playing, but that only works if you understand the transposition.
I think a lot of communication gets fouled up this way. We all have accumulated experience and wisdom to share with others, but sometimes we're missing the key that will allow us to translate that in way other people can use. And there's no way to know what you don't know, so it's hard to be on guard for this kind of mistake when you are the one trying to impart knowledge to someone else. Instead, I think we should be watchful for potential problems on incoming knowledge. Ask yourself: How might someone working in an area related to mine get confused? If you're a math teacher, for example, consider including "translations" for current math terminology to those of previous generations, so parents can usefully be involved with their children's math work. The world depends upon knowledge journeying from one mind to another, and we have to ensure that it survives the trip.