Assessing Progress

It's difficult to assess how efficiently one is progressing, when writing a book or compiling a lecture. It's not like a university semester or an academic thesis, where one has waymarkers. Two of the ways I try to assess how efficiently I am progressing: 

1. How much energy have I used up? One's "weariness meter" says a lot.

2. How much quality writing have I produced? That's how I am faring.