Where is the instruction?
DuoLingo Chinese asks us to translate Chinese words it has not taught. In fact, it never teaches the meaning of any words. I find this so perplexing I feel like I must be missing something. DuoLingo teaches the pronunciation/pinyin pairs. It teaches the pinyin/character pairs. But it never teaches the meaning of characters. This can't be right. What have I missed?
The English translations are available as hints. You don't have to use them, and in fact recourse to them indicates to Duolingo that that word is one you need more help with, so it will likely appear more often so as to help you learn it, given Duolingo's spaced repetition system.
Use the Strengthen button when you've finished a lesson. It'll be a mix of pinyin matching, character identification, and sentence translations, where there you can hover over the characters for a translation. Some units do have more of these sentences than others. Of course there should be some sentences showing up in the lessons as well, as phb2013 said.
I certainly have my quibbles with the set-up, but at least I find it's a whole lot easier to remember what the characters mean than their pronunciation (and I've seen others mention the same problem), so I get the preponderance of sound matching.
That is unfortunate. 130 million humans are born every year, and all of them learn language directly from their environment. We're not wired to learn through an intermediary language. Too bad. DuoLingo will still be useful to me as high-tech flashcards for Chinese I learned elsewhere.
What part is unfortunate?
Few non-infants have native speakers of a language willing to let them hang around saying nothing for a year plus before uttering any cogent sounds. Trying to extract language lessons for adults from the process of first-language acquisition is a fraught endeavor.
But if you have the opportunity to participate in an immersion Chinese language program, then by all means it should outclass Duolingo. If it didn't, I would say there was something seriously, seriously wrong.
I think translation-as-pedagogy is unfortunate. I've taken classes, tried Pimsleur, used apps and videos, but the direct method (eg., depicting a person reaching out to shake your hand while saying "hello" in the target language) seems far faster and more effective.
I take your point about non-infants and native speakers. Rosetta Stone, though, takes a good crack at the direct method. It's not full immersion, of course, but it's effective.
To phb's question, I understand basic greetings, pronouns, colors, and counting to at least 100. I can read about 120 characters. I can speak simple sentences. My hope with DL was to expand my vocab and listening comprehension.
I've used Rosetta Stone. Not a fan. For me the pacing was simply far too slow, and it would up being by and large a waste of time. I could imagine it would work better for a language with very little inflection like Chinese. I used it for Russian. Sure you're not translating from English, but puzzling out their pictorial representations and weird exercises was no cakewalk. (Like if two people are shaking hands across a conference table, is the word you're supposed to learn one that means "handshake" or one that means "agreement"?) Russian wasn't my first foreign language though, so I had the advantage of having learned to speak without translating.
You might like the FluentForever app when it comes out (it'll probably be a while). I think the method will be designed to avoid translation while potentially avoiding the problems (as I see them at least) with Rosetta Stone.