You know when you can't see the forest for the trees? When the details are so overwhelming, complicated or just plain plentiful that discerning the overall idea becomes simply impossible? Try taking some leave.
I have just resumed my PhD study after 12 months of maternity leave. I have come back refreshed and ready to work, but more importantly I can't remember what I was doing before I went on leave. I do remember my research question. I do remember that I have collected the artefacts and completed some initial analysis. I remember only the results of the analysis that excited me. In other words, I have only retained a small amount of the last 3.5 years of work. While that may sound depressing, I think it is actually useful.
We don't retain a lot of what we learn. Heaps of education theory has been dedicated to helping teachers use strategies to increase knowledge retention but I think this Gotye parody hits the nail on the head http://www.youtube.com/watch?v=VxkHM4DUDKM. His teacher probably had a rock star cotton gin mnemonic.
Maybe its a good thing that people forget a lot of the details because then clarity can sink in, paring away the bulk until left with a skinny idea. Frankly, an idea that has been on a diet is a lot easier to lift.
Here's two examples of what I mean. Before I went on leave, I could not (for the life of me) come up with a model that illustrated my adjustments to the analysis. After leave it struck me and the resulting model is beautiful in its simplicity (as well as in its shades of blue). Before leave I didn't fully understand my base analytic approach. It seemed too complicated and cumbersome. After leave, my analysis chapter is almost complete after a brain wave. Again elegance in simplicity. I'm not saying I have it right but I have enough years of teaching behind me to know that the simplest answer is usually the best. Apologies if I sound arrogant.
I should say that I didn't entirely take leave from thinking about my PhD but I did take leave from the content. I joined Twitter and began networking with PhD students from around the world (usually in the middle of the night while feeding my newborn). I also began to read and follow PhD aficionados like @thesiswhisperer, @PhDForum, @drwcarter and @Thomsonpat. I think this meta-cognitive time is time well spent. I began to think about how I learn and synthesised some of my pre-leave feedback. The results? I now have techniques that have (so far) stopped my tendency to tangent and become bogged down in interesting but irrelevant ideas.
For example, I write using pomodoros, something I heard about watching my first #phdchat. The 25 minute writing sessions keep me on track because my mind tells me I have to get the section finished before the alarm goes off. My learning style tells me that there is no time to wander because the clock is ticking (probably from years of taking and conducting exams). Additionally, the 5-10 minute breaks give me time to reflect on whether what I achieved in the last 25 minutes was relevant; if not, I have only wasted 25 minutes of work, not a day.
So, if your PhD is getting a bit much and you can't see the forest for the trees, try taking some leave. It doesn't have to be a year. Maybe an afternoon, a weekend or a fortnight. But remember some of the finest things in life (like toddlers) are best when rested.