my post on motivation for my input on concentration. I've quickly given an answer in the comments, but I'd like to expand on the topic in a full post.
Concentration is not my natural strength. With a concentration span of about 20 minutes and my generally super-scattered brain, I've needed to work hard when I started university and couldn't simply study 20 minutes before an exam anymore.
My first years at university were not a big success (or at least, my grades were not as good as I would have wanted them to be), mostly because I didn't put my concentration where I had to.
Bit by bit, I started to learn how to focus (still working on it though!), and at the end of my studies, I was back to studying very few hours per day during exams, but with more concentration and dedication - which also resulted in significantly higher grades.
Therefore, I've gained some experience in observing my own habits and how to improve your concentration. I've already given my 10 tips for a better concentration, but here you can find 5 easy steps to implement and work towards a better concentration:
1. Know your tools
Identify the length of your concentration span: during a few work days, note down precisely how long you stay at one task. You can as well use a software tool, like ManicTime, to tag your time slots (but then, make sure you consistently tag whenever you leave your thesis document and go browse online or run off to the coffee machine).
Knowing how your brain works regularly is absolutely important to improve your concentration. Only once you know what you can work with, you can also work towards expanding your concentration span.
Action: map your concentration span!
2. Clear goals
This example should give you a sense for setting clear goals: compare "write thesis from 8am to 6pm" on your to do list to "write 400 words on paragraph 5.3.4 in thesis between 10am and noon". Setting clear goals, and knowing what precisely you need to do in which time slot, allows for less drifting off in thoughts.
Action: take your planning tool and schedule clear goals.
3. Frequent breaks
If you want to have several hours of deep concentration in a work day, then it is absolutely important to unwind every now and then. In the Pomodoro technique, 25 minute sets of concentration are alternated with 5 minute breaks, and a longer break after 4 Pomodoros. If you try to force yourself to sit on your chair for hours and hours, your mind will start to wander and you'll make slower progress. The key is to take short, but frequent breaks such that you can stay at a decent level of concentration throughout the day.
Action: build some air into your schedule and try a timing technique.
4. Take care of your body
You can't concentrated when you're tired, sick or generally unwell. Therefore, it's important to find time to prepare wholesome food, work out, relax and get your hours of sleep. Sleep deprivation is one of the most common reasons for poor concentration.
Action: Take that planning tool again, and schedule time to take care of your health (gym, cooking a healthy meal,...) or skip some commitments to safeguard your 8 hours of sleep.
If you want to improve your focus over a longer period of time, there is no better way than to work out your brains. Meditation is indeed nothing more than a good workout for your brain (plus all the benefits that are associated with meditation!). As a researcher, you're "paid to think", and therefore taking good care of your brain and optimizing its performance is very important.
Action: Look at your schedule. At what point during the day can you guarantee 5 minutes for meditation?