Just reading isn’t enough if you want to use that information later on. These tips help you to remember what you read.
Read with a purpose
Think why you are reading, and how the text helps you to reach your goal. This makes it easier to see the parts that are important for you.
Use the SQ3R method
SQ3R is an active reading and note-taking method that helps remembering the key points of a text.
First skim the material
Look at headings, images and captions, and read the abstract. This helps to get a sense of the whole material and subject.
Focus on blocks of text
Instead of reading word-by-word, learn to focus on larger blocks of the text. Besides making reading faster, this also helps understanding the whole.
Highlight, but not too much
Highlight only key words and ideas. After reading few paragraphs or pages, try to remember the key ideas. Then check your highlights to see if you remembered all correctly.
Think in pictures
Create a mental image of the content. Or try to experience being a part of the situation, instead of observing it from outside. Both require understanding the content and help in memorizing. Mind maps are also good for making connections between concepts.
Every few pages or after finishing a chapter, stop and think what you just read. Ask questions about the content. (What this means? How this helps me? What wasn’t said? How this can be applied? Where this has connections to?) Do you have real-world problems to solve? If not, find some from textbooks or old exams.
Explain the concept to someone. Summarize the text with your own words. If you can’t, re-read.
Make flashcards, paper or electronic. They are good for memorizing facts.
Have a break when you can’t concentrate
Stop reading for a moment after you have reached your attention span. (Typically 15 minutes for hard content.) Learn to concentrate longer.
Rehearse after reading
When finishing your reading session, rehearse again as instructed above. Repeat twice during the day, and once per day for a few days.
Read the text again. This not only helps you to remember, but also to understand better (since you have a sense of the whole) and to correct your (possible) misinterpretations.
Bill Klemm: 8 Tips To Remember What You Read
Quora answers on How can I read quickly but still understand and retain everything that I read?