According to Andrew Feenberg, an instrumental theory of technology assumes that technology doesn't necessarily change an organization's (or a culture's) practices. An instrumental theory focuses on people's uses of technology, rather than on the technology itself. This places the emphasis on a person's use of technology, rather than on its design; moreover, this suggests that one must look at use (rather than design) when making a value judgment. So, it's not that a technology is inherently bad or good; it's that people are using the technology either poorly or well.
An instrumental approach in writing center literature might suggest that on-line work & interaction isn't fundamentally different from face-to-face interaction. Such an approach might also lead one to question how students and tutors are using a technology, rather than questioning how the technology itself changes interaction.
On the other hand,