Conversation with Duolingo
I think that we should be able to practice our skills by having a conversation with the computer, or something like that.Like:
Duolingo: Bonjour. Ca va bien?
Student: Oui, je suis, merci.
Duolingo: C'est bonne.
Student: Ca va bien?
Duolingo: Oui, merci.
Something like that. Wouldn't that be really cool?
There are some programs now in the common domain that can mimic conversations, most famous being Elisa http://tinyurl.com/znlug (The Wikipedia entry for it). So it's not the conversation part that is impossibly difficult for programmers; the extra requirement of correctly recognizing whether your response has errors or not is the tough part. And after all, Duolingo is already doing that in a more limited way. Maybe we are exaggerating the difficulty (such as: Question - "What sits on a hill and howls at the moon and is made of concrete?" Answer: "A coyote. I just threw in the concrete to make it hard."
I think you're really underestimating the problem. You can use something like Eliza to have really basic, superficial mock conversations, but the answering is the problem.
In the original Eliza implementation, what is being considered is the response of the computer - in this case, we're more interested in the response of the user.
You can break this down into two problems:
"Qué quieres hacer hoy?"
We need to figure out:
A) Is utterance X a grammatically correct Spanish sentence?
B) Is utterance X a possible response to the question?
For extremely superficial questions, "How are you? Do you have Siblings? What are their names?", maybe this could work. Provided it is made explicitly clear you can only say "Estoy enferma/estoy cansada" etc and not "Estoy cansada porque anoche...".
However, given that I believe Duolingo stores the responses to translations versus has some awesome machine translation tool to figure them out on the fly, the possible response to open ended questions like this are seemingly infinite.
If you are at a level where you can hold a decent basic conversation (where are you from, what do you do for a living, what are your hobbies, what music and books do you like) you might want to check out Verbling.com They pair you up with someone who is native in the language you are learning, who is learning your native language. You can have video-audio chat, or just audio chat. You also have the ability to type into a text chat area, which is handy for spelling a word out or sharing a link. Verbling is not about teaching the basics (which Duolingo excels at) but it is all about getting you out of your shell and actually speaking the words.