In my experience, they don’t even tend to be very good at teaching vocabulary - unless I guess, you’re willing to do lots of review exercises (at which point, seems like you might as well use flash cards).
Some of the following is a bit theoretical and based on my own brain. I have not tested it out with an app design of my own and it may not apply to all kinds of brains (I know not everybody remembers the same things or in the same way):
My working hypothesis is that part of the problem is a lack of variety for one and a lack of context for another. As an example, 我 (I) in Chinese is relatively easy to remember because you will organically encounter “I” over and over, and in a wide variety of different contexts. Now for comparison, consider characters like 叉子 (fork), 勺子 (spoon), and 筷子 (chopsticks). You might encounter these in the context of ordering food at a restaurant (which makes sense for an app trying to help out tourists, right?). But you probably won’t see distinctions like “I would like a spoon because I am eating ice cream” or “I would like a fork because I am eating pasta”. Both would sound awkward as real sentences to order with and just in general as things people are going to tend to casually say, but in terms of associations between concepts, I think it matters the absence or presence of that “because” clause. Without that context, all your brain has to latch onto is the generic concept of ordering food. So maybe your brain bundles those words under associations to do with ordering food, but it doesn’t distinguish on a finer grain level beyond that and as a result, it’s hard to remember which is which. You might remember there are these something 子 words that go together with ordering food, but beyond that, it’s harder.
So the apps tend to focus on common phrases and common words and things such as that, but they’re not focusing enough on how the brain processes concepts and remembers them.
In my experience, they don’t even tend to be very good at teaching vocabulary - unless I guess, you’re willing to do lots of review exercises (at which point, seems like you might as well use flash cards).
Some of the following is a bit theoretical and based on my own brain. I have not tested it out with an app design of my own and it may not apply to all kinds of brains (I know not everybody remembers the same things or in the same way):
My working hypothesis is that part of the problem is a lack of variety for one and a lack of context for another. As an example, 我 (I) in Chinese is relatively easy to remember because you will organically encounter “I” over and over, and in a wide variety of different contexts. Now for comparison, consider characters like 叉子 (fork), 勺子 (spoon), and 筷子 (chopsticks). You might encounter these in the context of ordering food at a restaurant (which makes sense for an app trying to help out tourists, right?). But you probably won’t see distinctions like “I would like a spoon because I am eating ice cream” or “I would like a fork because I am eating pasta”. Both would sound awkward as real sentences to order with and just in general as things people are going to tend to casually say, but in terms of associations between concepts, I think it matters the absence or presence of that “because” clause. Without that context, all your brain has to latch onto is the generic concept of ordering food. So maybe your brain bundles those words under associations to do with ordering food, but it doesn’t distinguish on a finer grain level beyond that and as a result, it’s hard to remember which is which. You might remember there are these something 子 words that go together with ordering food, but beyond that, it’s harder.
So the apps tend to focus on common phrases and common words and things such as that, but they’re not focusing enough on how the brain processes concepts and remembers them.