Incremental Reading: Reading 10 Books at the Same Time

The title can be misleading regarding the timespan “at the same time”. My meaning of “at the same time” is the one from Incremental Reading (IR). If you haven’t, please read SuperMemo’s Incremental Reading: Explained. Also, you may consider this article being “SuperMemo’s Incremental Reading: Explained Again”.

Meaning of “reading 10 books at the same time”

We can try to understand the timespan “at the same time” at two levels: one hour and one month.

Timespan: one hour

The official documentation explains it this way:

We do not mean the same “moment of time” but the same “period of time”. We do not envisage a user with a thousand of monitors, nor a user photoreading thousands of articles flashing in front of his eyes in a second. We, naturally, mean having thousands of articles in the learning process.

“At the same time” doesn’t mean opening two browsers side by side and switching your eyes between the two books. It’s about starting to read book B before you have completely finished reading book A. For a given hour, I may spend the first 20 min reading book A, then 30 min on book B, and finally 10 min on book C. So the sequence is the following:

20 min on book A -> 30 min on book B -> 10 min on book C

The myth of multi-tasking

When you feel like you’re multi-tasking, or paying attention to two things at once, you’re actually switching back and forth between the two things you’re trying to pay attention to. - Understanding How We Learn: A Visual Guide

Multi-tasking doesn’t mean paying attention to many things at the same time. It means switching back and forth between the two things. By the same token, IR doesn’t mean paying attention to two books at the same time, just like the way most people see in multi-tasking. Rather, it’s about switching back and forth between the books. Both multi-tasking and IR are not about “paying attention to two things at once”.

Timespan: one month

IR also means “reading 10 books at the same period of time.” At a specific timespan, I have started reading 10 books. Say, in this month, I’ve borrowed 10 new books. In this month, I will not finish reading, from start to finish, any one particular book. I’ll be at 2nd or 3rd chapter across all 10 books.

At a given day, I will go back and forth between each book. It doesn’t mean I have to read some parts of all 10 books every day. One day I might only touch upon four books, other days I might focus solely on one book. It’s up to you. This way, it will take me longer to finish a book, from start to finish. The most important aspect is that I’m reading them “on all fronts.”

Graphic Illustration of Incremental Reading


There are 30 circles in total. Each circle represents 1 day, so 30 days in total. Suppose you’re reading 5 books, hence 5 different colors. To simplify matters, let’s also suppose you can only read 1 chapter of 1 book in 1 day. Therefore, each circle also represents 1 chapter of the same book. In other words, the first circle means reading chapter 1 from Purple Book; the next day you read chapter 1 from Orange Book and so on.

If we zoom in and isolate each color:


You can see that there is spacing between each color. For Purple Book, you read chapter 1, then it’s 2 days later before picking up chapter 2, then 13 days later before moving on to chapter 3.

A traditional approach would be:


It means for the first 5 days, you focus solely on Purple Book. Each day you read 1 chapter from Purple Book. By the end of 5th day, you’ve finished Purple Book, so on 6th day, you move on to Orange Book and so on.

The total time spent on each book is the same, just stretched longer

Refer back to the above scenario. For both IR and the traditional approach, you finish 5 books in a month. It’s just that for IR, the time for each book you read from start to finish is stretched longer. In other words, the rate of reading (books per month) hasn’t changed, but the reading timespan for each book has increased. IR means taking longer to finish each book.

If you’re familiar with programming, “at the same time” in IR is similar to concurrent programming, not parallel programming (Image source):


Parallel programming is the description “photoreading thousands of articles flashing in front of his eyes in a second”, which is what most mistake the meaning of IR for.

Why you would want to read 10 books at the same time

In short, IR takes advantage of the interleaved practice and spacing effect. “Read many but slowly” is the best phrase to capture this idea. Slow and steady wins the race.

Analogy: planting a tree

Reading a book over a longer period of time, say, 3 months, allows you to plant the seed and let it take roots. Connecting ideas, organizing pieces, integrating new ideas with your prior knowledge take a lot of time. Sleep helps a lot. You want to read some ideas, sleep on them, let them “simmer on the back burner (unconscious mind, so to speak).”

Finishing a book in a week is like planting only one seed for that week. Pouring all the available nutrients to a plant is not efficient because there is only so much it can grow in that short period of time. Can it absorb all the nutrients? Probably not. Not only are you taxing your working memory, you also don’t give it enough time to make its way into long-term memory. It’s like building a sand castle: easy come, easy go.

On the other hand, reading 10 books at the same time, but over a longer period of time, is like start planting 10 seeds altogether. Every seed has more time to grow. You are gradually allocating the available nutrients for each plant. Not overloading the plant means it can fully absorb the nutrients. Individual seed will grow slower, but they’ll grow better (think of long-term memory).

Does it mean I can only read a book in 6 months? Of course not. You want to read each book slowly, but it doesn’t mean you can only read 1 book. You can read 10, 20 or 30 books. It’s all up to you.

I’ve dived deeper into the benefits of IR in The Significance of Incremental Reading: Part I and Part II.

I never need to read thousands of articles in parallel! Why would I need incremental reading?

“Reading thousands of articles in parallel” is more like “I have 1,000 unfinished articles.”

Lastly, “Reading many books at the same time” is not the same as speed reading. It doesn’t mean finishing 10 books in 3 days. I don’t believe in “speed reading.” My reasons behind are from 3 Steps to Read Faster – Truth on Speed Reading and Do Speed Reading Apps & Techniques Really Work?.


I hope I’ve convinced you to give IR a try. I wholeheartedly believe this is a far superior way to read and learn. The video Starting with SM Going through the IR Manual is currently the best video on getting started with IR.