I'm a young graduate student in the physical sciences. As far as I can tell, the purpose of graduate school is to learn to become an independent researcher. This means becoming a good writer, solving novel problems, publishing good papers and becoming an expert in your field.
The trouble is that these goals are horribly vague. I have no clear idea how to get from my current skill level to that of an "independent researcher". There is some mix of learning from a textbook, reading papers, attending classes and coming up with new ideas. But I find it hard to break it down into subtasks and be deliberate with my time. Instead I find myself wandering from textbook to textbook, learning this and that, solving this small problem and that small problem, wondering if I am really spending my time on the right things.
In many other domains, it's easy to tell if you are getting better on a short-term basis. For example, in bowling you can practice and see if your score goes up. In chess, if your rating goes up. In music, if you're hitting the notes. But in research there is no such metric. This leads me to feel discouraged and unsure of my progress and myself.
What are general, realistic research goals that I can set on a daily, weekly and monthly basis?
Some of my ideas are setting a target for: number of papers read, number of practice problems solved from a textbook, number of hours spent writing about a technical topic, number of hours worked in a state of deep concentration.
The most relevant question I could find is here: Is it possible to measure/evaluate one's progress or development in quantitative terms?