Explanation in the Digital Age

My classes are already starting to blur together. It happens to me every semester, but usually not until after midterms. I think it's because almost all my classes are writing based -- so they just feed off each other. Currently, I'm working on an assignment for my technical writing class in which I examine a piece of technical writing and perform a rhetorical analysis on it. Part of the assignment is to analyze and critique the author's ability to provide enough background knowledge for the reader to follow along (if applicable). 

Now, because I'm also taking Writing for the Digital Age, my brain is constantly picking apart current communications. That's when I got to thinking about the necessity for technical writers to provide background information. In our Google age, is there a point to explaining jargon and other highly specific information in every case?

Let's take, for example, a knitting pattern.

Above is Robin Ulrich's "Greyhaven Cowl" (Ravelry link for those interested: http://www.ravelry.com/patterns/library/greyhaven-cowl).

I've been pining after the Greyhaven Cowl for a while, and finally broke down and bought the pattern. I haven't begun knitting yet, but a preliminary glance has got me feeling pretty good. The pattern is neatly organized, there are charted and written instructions, and repeats are even color coded. It even includes instructions for binding off and blocking, which is above and beyond the call of duty.

But, as nice as all that effort on the designers part is, I don't think she needed to do all of that. I wouldn't have blamed her for a second if she just charted out the pattern and didn't write it as well, because if I didn't already know how to read a chart, I could just Google it. Same for blocking and binding off. The information is already out there and readily available.

What is our responsibility to explain processes or jargon that's easily looked up by those who don't know the information already? I'd love to see what you think in the comments.

Also, on an only semi-related note, I think I'm going to make these socks for myself. They're just too cool.

They are Claire Ellen's "Pippin Socks" (http://www.ravelry.com/patterns/library/pippin-socks).