I totally understand the confusion about this as it's not really a thing you can pick up and buy, but to be able to identify what it is you already need to know what you are looking for. Or trust someone that does.
If I give you a transcription of a walking bass line that I lifted from a record that isn't academic music in this. Yes we can analyse it and understand what is going on but we are still ultimately at the mercy of someones approach and style. IE how they use rhythm, passing tones, chromatics etc is all dictated to us by that player. You are studying a snapshot of them in time. Now there is absolutely nothing wrong with this at all by any means, there is tremendous value in it but the flaw is you are learning someone else approach or compositing something from various people you study. This is valuable and largely how people begin to develop individual styles, or at worst case just sound like a clone... which happens a lot.
Now an academic approach to that would be to take the same chord sequence and study every possible permutation of a chords. If it's a triad there are something like 90 odd permutations from root position to 2nd inversion. That number goes up the more notes we add to each chord. But the study of each permutation alone is really drilling in the pure information alone. You aren't accounting for style or substance or a genre etc etc you are simply dealing with the raw data of the notes within a chord and the possible ways to play them and how to do it on the instrument.
So you can play through the changes using all the permutations of only root position, then 1st inversion, then 2nd inversion etc. Which is harmonically perfect to use a Jeff phrase because there is not a single note that doesn't outline the harmony. In the process of doing that you'll be a much better bass player because you have spent hours and hours over months and years really learning the instrument to work through all of that.
It's not going to sound amazing on the gig but it's not going to sound wrong either, but you'll be able to manipulate that information as you see fit rather than manipulation the information you've learning from someone elses manipulation of the information. Or Chinese whispers to sum it up.
Absolutely transcribe stuff and analyse it as well. There is a wealth of information to be learned from that but Jeff's approach absolutely works as well since you'll have a far more thorough understanding of the raw material to create stuff with.
