Ok, so we've established that the Zone of Proximal Development (ZPD) is the difference between what a learner already knows (their actual development level, developed "retrospectively"(Aljaafreh & Lantolf, 1994, p. 468)) and what they can do when assisted (the ZPD, developed prospectively (ibid)), and it is virtually impossible to discover the novice's ZPD without dialogic negotiation. But why is it important to know the ZPD? After reading Aljaafreh and Lantolf's (1994, 1995) articles I have a greater understanding of its importance. 

We talked about how learners with different distances (in terms of years) between their actual development level and ZPD have different developmental ages, and now there is another way to look at it in regards to giving feedback. Aljaafreh and Lantolf (1995, p. 622) provide a 12 step framework for feedback that goes from implicit to explicit feedback. If a learner shows that they are able to correct their errors by themselves, then this would be level 0, or implicit feedback. However if the expert gives examples of the correct pattern because other forms of feedback have failed, then this is considered level 12, or explicit feedback. When the negotiated feedback moves up the scale towards more implicit means, this is called microgenetic development. 

As language teachers, we have to try and get our learners to the more implicit levels of feedback for them to show their true development levels. We have to "lure" them into "functioning in an appropriate way without making the task frustrating" (Wertsch, 42). The earlier in the list the learner can provide correct language performance, the more developmentally advanced they are. This means that "Development in the L2 is therefore not only reflected in the learner's ability to generalise what had been appropriated, but is also revealed through the kind of help that is jointly negotiated between experts and novices" (Aljaafreh & Lantolf, 1994, p. 480). 

The responsibility of the novice's linguistic performance is firstly distributed between the novice and the expert, with the expert having more control. Following this the control is "gradually appropriated" by the novice, they move away from reliance on the expert towards reliance on the "self". I feel that this part here may be one major difference between the East and West in terms of expectations of the novice and the expert. Those in Eastern contexts may find it more difficult to break away from the teacher here due to being accustomed to teacher-centred learning. Likewise, the teacher may feel uncomfortable breaking away here, but it is important because without the teacher (expert) breaking away, there can be no real development (Aljaafreh & Lantolf, 1994, p. 480).