What do "recast" and "uptake" mean?

(answer from BB)

Uptake (Lyster and Ranta’s definition) refers to a learner’s observable immediate response to the corrective feedback in his/her utterances.

Recast is an implicit corrective feedback, for example, a repetition of a content in a grammatically correct way. In other words, it paraphrases of a learners incorrect utterances that involve replacing one or more of the incorrect components with a correct form while maintaining the meaning .

Roy Lyster and Leila Ranta (1997) developed an observation scheme which describes different types of feedback teachers give on errors. They also examined students’ uptake. They identified 6 types of feedback and one of them was recast:

S1 Why you don’t like Mark?
T Why don’t you like Marc?
S2 I don’t know. I don’t like him

They made observations in content-based classroom. Their results showed that recasts accounted for more than half of the total feedback provided in classes.

Uptakes were least likely to occur after recasts and more likely to occur after other types of feedback. More Uptake was a result of elicitations and metalinguistic feedback, which also proved to lead to the higher probability of corrected form of initial utterance.

In the content-based second language classrooms students are less likely to notice recast since they may assume that the teacher is responding to the content, rather than to the form.

Several other studies proved that recast is the most common form of corrective feedback and it appears to go unnoticed by the learner most of the time.

Other research found that learners are willing to answer to a recast when it is directed on somebody else’s speech. So even if they do not lead to the uptake of the error producer, they do get noticed by those who overhear.

Ideally recast leads to uptake. Further research findings demonstrate that recasts work in a language-focused class (as opposed to content-based) with adult learners, especially those who received a grammatical instructions prior to observation period. In the language-focused class students are more likely to perceive recasts as a feedback on the form of their utterances.

Pros “recasts”:

Indirect and polite way to correct errors
It doesn’t embarrass student
It doesn’t interrupt the flow of interaction
Adults are responsive
Opportunity for learning of those not speaking but listening

Cons of “recasts”:

Recasts can stay unnoticed

They do not work in all contexts (content-based)
Shift center to the teacher
Children are least likely to recognize recast as feedback
Context-limited ( only advanced students can truly employ this kind of feedback)

Yes, I am pro-recast person. First, all what was mentioned in Pros are true and doesn’t take extra time. As far as my particular context is concerned, I see recast as the anxiety-free way of correcting errors that have to be corrected. Mu students want to have their errors corrected. I want them to become fluent. Recast seems to be the least interruptive path in speaking classes.
Before we start communicating I ask students to do me a favor. If I repeat something after them, they repeat the same exact thing after me. It makes them hear not only correct version, but saying it themselves, which is more important. Depending on our focus we can omit repetition. As I have mentioned, level of the language proficiency matters. With lower level students I would ask them to pay more attention to uptakes, while advanced would do it themselves and most of the time silently.
The idea of recast is similar to the idea of scaffolding in Conversation Theories.

Source: http://ows.edb.utexas.edu/site/teaching-russian-e-portfolio/what-do-recast-and-uptake-mean-answer-bb