Give 'em the real thing

I've been thinking about our discussion related to isolated skill work compared to the whole-part-whole philosophy espoused by Regie Routman. Years ago I heard someone describe to me how tellers were trained to detect counterfeits. According to Bankers Online training is based heavily on the trainers being able to feel the difference between counterfeit and authentic money. This is the most effective means because the tellers handle so many real dollars day after day that when they feel the fake, it stands out like a sore thumb . (No pun intended!)

I was thinking of this in conjunction with practice exercises that provide errors for students to correct. What evidence is there that this isolated skill practice transfers to independent writing? It makes more sense to me that students will benefit from more time spent immersed in reading. Read alouds, partner reading, guided reading, and independent reading all seem to me to have a greater impact on students' knowledge and facility of language.

I'd love to read the thinking of others on this.