I'd like some actual empirical evidence that saying "this is tricky" or "this is difficult" actually de-motivates ("turns off") students. It might, but I can also plausibly imagine the reverse. What if you say "oh, this will be easy and fun!" and then they have trouble with it? IMHO, that might send the message that they're just dumb. At least when you say "it's tricky" and they struggle they may not think it's their fault and might be willing to keep trying.
I think you could spin a lot of plausible pedagogical theories, but I'd be more interested in seeing some actual evidence.
The other thing to remember is that teachers speak to roomfuls of students at a time, not one student at a time. If you've got one student, then sure, you need never explicitly say that a particular concept is tricky. You can determine trickiness by trial-and-error: If the student gets confused at any point, explain again, but otherwise just keep going.
But with a whole roomful of people it's not as if you're going to fool them by avoiding the word "tricky": They're going to know when you cover something that is tricky, because half the audience will be confused, and the other half is then going to have to observe you explaining the tricky thing over and over again to the first half.
I think "this is interesting" might be a better introduction.
Also, in my experience, when people (especially teachers and professors) say "this is tricky", it is often in part or in whole because they are only giving you a partial explanation -- part of the picture.
It's "tricky", because they are telling you to accept certain things prima facie when actually (for me, at least) they'd make a hell of a lot more sense and be easier to absorb with a more complete description/explanation.
Some of the time, this is because they don't really understand the topic themselves. Other times, one or another pedagogical inclination or requirement makes them avoid a deeper discussion. ("I don't have time" or "We don't have time" or "That's beyond the scope".)
> What if you say "oh, this will be easy and fun!"
That is same problem as saying "Oh, this is hard and tricky." The author didn't seem to suggest to tell students things are easy, which is misleading and harmful, but rather he used the example of art teachers where the students are not told that things are easy but rather they need to practice and put in a lot of effort. Hell, he didn't say the word 'easy' once in his blog entry.
Lecturers and many others seem almost afraid to say "You're going to have to work hard." and then stand by that statement.
I'm currently at university and I've seen exactly what he has said. Lecturers and students saying x is hard and tricky and for most of the other students here that seems to have demotivated them. I think the current schooling system here in Australia and in other countries in the world where I've spent time or have friends from is horribly flawed in many ways and what this blog entry about is just one of those flaws.
I wonder if any of that has to be said at all? What if a lecturer did not set this prejudice upfront at all? However helpful emotions are in the learning process, saying "this is tricky" or "this is easy" is not going to help.
Instead, play on other emotions. Explain the theory, show real life examples, simple tricks, stuff like that, surprise them. But don't say "this is hard" or "this is easy". Let them decide.
I'm just citing personal experience. I would be very interested to see studies that clearly backed up or refuted my perceptions. The real machinery at work is probably more interesting than I imagine, and definitely more interesting than I make it out to be in the article.
I think you could spin a lot of plausible pedagogical theories, but I'd be more interested in seeing some actual evidence.