In the supermarket yesterday, I found myself with a rapid-onset desire for mayonnaise. I would have bought some too, had I know what the Russian word for mayonnaise was. So, instead of satisfying my craving, I went home to look up the word in my Russian-English dictionary, and eat some more baked beans. This process is a variation on what we in the language-education industry call "Task Based Learning".
Imagine my ambivalence when I learned what the translation is. One the one hand, it's one word fewer for me to learn. On the other hand, I counldn't help feeling that I might have guessed for myself.