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Incremental reading


  1. What is incremental reading?
  2. Advantages of incremental reading
  3. Five basic skills:
    1. importing articles
    2. reading articles
    3. converting articles to questions and answers
    4. repetition and review
    5. handling knowledge overflow
  4. History of incremental reading
  5. Summary
  6. FAQ

What is incremental reading?

Incremental reading is a learning technique that makes it possible to read thousands of articles at the same time without getting lost. Incremental reading begins with importing articles from electronic sources, e.g. the Internet. The student then extracts the most important fragments of individual articles for further review. Extracted fragments are then converted into questions and answers. These in turn become subject to systematic review and repetition that maximizes the long-term recall of the processed texts. The review process is handled by the proven repetition spacing algorithm known as the SuperMemo method.

Incremental reading converts electronic articles into durable knowledge in your memory. This conversion requires minimum keyboard work:
  • Input: electronic articles (e.g. collected from the net)
  • Output: well-remembered knowledge (quizzed regularly in the form of questions and answers)

Warning! Incremental reading may seem complex at first. However, once you master it, you will begin a learning process that will surpass your expectations. You will be surprised with the volume of data your memory can process and retain!

Advantages of incremental reading:

  1. Massive learning: possibility of studying a huge number of subjects at the same time. In traditional reading, one book or academic subject might need to be completed before studying another. With incremental reading, there is virtually no limit on how many articles you can study at the same time. Only the availability of time and your memory capacity will keep massive learning in check
  2. Creativity (the association bonus): The key to creativity is an association of remote ideas. By studying multiple subjects in unpredictable order, you will increase your power to associate ideas. This will immensely improve your creativity. Incremental reading may be compared to brainstorming with yourself
  3. Understanding (the slot-in factor): One of the limiting factors in acquiring new knowledge is the barrier of understanding. All written materials, depending on the reader's knowledge, pose a degree of difficulty in accurately interpreting their contents. This is particularly visible in highly specialist scientific papers that use a sophisticated symbol-rich language. A symbol-rich language is a language that gains conciseness by the use of highly specialist vocabulary and notational conventions. For an average reader, symbol-rich language may exponentially raise the bar of lexical competence (i.e. knowledge of vocabulary required to gain understanding). Incremental reading makes it possible to delay the processing of those articles, paragraphs or sentences that require prior knowledge of concepts that are not known at the moment of reading. The processing of the learning material will only take place then when the new information begins to slot in comfortably in the fabric of the reader's knowledge. Incremental reading makes it possible to tackle the hardest material that might normally seem unreadable
  4. Counteracting entropy: The web is a goldmine of information. However, rarely do we find step-by-step articles that provide all information and entirely satisfy our needs. In scientific research, acquiring engineering knowledge, studying a narrow topic of interest, etc. we are constantly faced with a chaos of disparate and often contradictory statements. Incremental reading makes it possible to resolve contradictions and build harmonious models of knowledge on the basis of the information chaos drawn from the Internet. Incremental reading stochastically juxtaposes pieces of information coming from various sources and uses the associative qualities of human memory to emphasize and then resolve contradiction
  5. Stresslessness. The information era tends to overwhelm us with the amount of information we feel compelled to process. Incremental reading does not require all-or-nothing choices on articles to read. All-or-nothing choices are stressful! Can I afford to skip this article? For months I haven't had time to read this article! etc. SuperMemo helps you prioritize and skip articles partially or transparently. Oftentimes, reading 3% of an article may provide 50% of its reading value. Reading of articles may be delayed transparently, i.e. not by stressful procrastination but by a sheer competition with other pieces of information on the basis of their priority. In incremental reading, instead of hesitating or procrastinating, you simply prioritize
  6. Attention. Incremental reading widely stretches the span of your attention. You will notice that a single paragraph in an article may greatly reduce your enthusiasm for reading. If you stumble against a few frustrating paragraphs, you may gradually develop a dislike of reading a particular article. You may even become fed up with reading for the entire evening. Incremental reading makes it possible to immediately move on to other pieces of information reducing the negative impact of frustration. It also makes it possible to split larger pieces into less intimidating portions. It allow you to read interesting bits before reading the boring bits. Those measures dramatically increase your attention. They also make reading fun. A skilled incremental reader is likely to develop an addiction to learning with all related benefits!
  7. Consolidation. Incremental reading combines the process of extracting pieces of valuable knowledge with memory consolidation. By the time you begin a standard spaced repetition process of well-formulated items (as in classical SuperMemo), your memory will often have already been established in a favorable context (i.e. context that makes remembering easier). This comes from the need to extract a given piece of information from a larger body of knowledge that provides your items with relevant context. This slow process of jelling out knowledge provides you with an enhanced sense of meaning and applicability of individual pieces of information. In addition, semantically equivalent pieces of information may be consolidated in varying contexts adding additional angles to their associative power. In other words, not only will you remember better. You will also be able to view the same information from different perspectives
  8. Prioritization: In incremental reading, you can precisely determine the priority of each article, paragraph, sentence or question. This will maximize the value of your reading time. This will also reduce the impact of material overflow on retention. You will always remember the desired proportion of your top-priority material. While the lesser priority material may suffer more from the overflow and be remembered less accurately. Priority of articles is not set in stone. You can modify it manually while reading. The priority will also change automatically each time you generate article extracts. It will change if you delay or advance scheduled reading. The priority of extracts is determined by the priority of articles. The priority of questions and answers produced from individual sentences is determined by their parenting extracts. Multiple prioritization tools will help you effectively deal with massive changes in your learning focus
  9. Fun. The sense of productivity might be one of the most satisfying emotions. This is why incremental reading is highly enjoyable. This only magnifies its powers. To experience the elation of incremental reading, you may need a few months of focused practice. You will first have to start with the basic tools and techniques listed in this article. Then you will need to master knowledge representation skills. Finally, you will need a couple of months of heavy-load incremental reading to perfect the details and develop your own "incremental reading philosophy". Last but not least, incremental reading requires good language skills, some touch-typing skills, and patience (SuperMemo will often want you to go against your own intuition). Although the material is originally imported from electronic sources, it always needs to be molded, shortened, provided with context clues, restructured for wording and grammar, etc. The skills involved are not trivial and require practice. In contrast to classical SuperMemo, where you focus on the review of the old material, incremental reading interweaves the old with the new. Novelty adds to the fun and efficiency of learning
Only SuperMemo makes it possible to implement incremental reading. Incremental reading requires continual retention of knowledge. Depending on the volume of knowledge flow in the program, the interval between reading individual portions of the same article may extend from days to months and even years. SuperMemo (repetition spacing) provides the foundation of incremental reading, which is based on stable memory traces that would not fade between the bursts of reading

See also: incremental reading from user's perspective by Len Budney. 

Five basic skills of incremental reading

Incremental reading requires skills that you will perfect only with passing time and growing experience. This overview will help you handle the most basic skills and help you make a start with incremental reading. The five basic skills are:

  1. importing articles to SuperMemo
  2. reading articles and decomposing articles into manageable pieces
  3. converting most important pieces of knowledge to question-answer material
  4. review of the material to ensure a good recall
  5. handling of the unavoidable overflow of information

Skill 1: Importing articles

To import an important article to SuperMemo, follow these steps:

  1. Select the imported text in your web browser and copy the selection to the clipboard (e.g. with Ctrl+C)
  2. Switch to SuperMemo (e.g. with Alt+Tab)
  3. In SuperMemo, press Ctrl+Alt+N (this is equivalent to Edit : Add a new article on the main menu). SuperMemo will create a new element, and paste the article. You can also use the paste button on the element toolbar or on the Read toolbar
  4. Optionally, use Alt+P to define priority of the imported article. Use the Percent field and remember that 0% is the highest priority, while 100% is the lowest priority 
  5. Optionally, use Ctrl+J to specify the first review interval. For example: one day for high priority material or 30 days for low priority material


Skill 2: Reading articles

Before you start reading articles, you can place the Read toolbar in an easily accessible location on your screen. The toolbar may be helpful before you learn to use the keyboard to access all its functions. Choose Window : Toolbars : Read, place the toolbar in a convenient place on the screen and press Ctrl+Shift+F5 (to save the current layout of windows as your default layout). If you do not see the Window menu read about levels.

This is the Read toolbar:

"Read" toolbar used in incremental reading in SuperMemo

Here is a simplified algorithm for reading articles:

  1. Choose an article: Import an article as explained earlier or bring up a previously imported article with Learn (Ctrl+L)
  2. Click the article to enter the editing mode in which you can modify text, select fragments, etc.
  3. Start reading the article from the top
  4. Extract texts: If you encounter an interesting text in the article, select it with the mouse and choose Reading : Remember extract on the component menu (or simply press Alt+X). Alternatively, you can click the green T icon on the Read toolbar () or on the element toolbar. This operation will introduce the extracted fragment into the learning process as an independent mini-article. If you would like to specify the priority of the new extract, choose Reading : Schedule extract instead of Remember extract (checked T icon on the Read toolbar) 
  5. Optionally, if you read a fragment that seems unimportant, select it (e.g. with the mouse). Then delete it (e.g. with the Del key) or mark it with the ignore font. To mark it with ignore font, choose Reading : Ignore on the component menu (or click the stop-sign icon on the Read toolbar)
  6. Optionally, if the selected fragment does not include all the important reading context, you will need to add this context manually. For example, if you are learning history, you may extract the following fragment from an article about Lincoln: On Sept. 22, 1862, President Lincoln issued the Emancipation Proclamation, one of the most important messages in the history of the world. He signed it Jan. 1, 1863. If you would like to extract the fragment related to signing the Emancipation Proclamation, you will need to change He to Lincoln and it to Emancipation Proclamation so that your fragment is understandable: Lincoln signed the Emancipation Proclamation on Jan. 1, 1863. You can use the Reference options on the component menu to easily add context to your extracts. Context added by Reference will be added automatically to all extracts of a given article. For example, select the text that you want to serve as the reference title of all extracts and choose Reference : Title on the component menu (or press Alt+T). This text will appear at the bottom of all extracts (in reference pink font by default)  
  7. Mark your last reading point: Once you decide to stop reading the article before its end, mark the last processed fragment as the read-point (e.g. with Ctrl+F7 or by choosing Reading : Read-points : Set read-point). Next time you come back to this same article, SuperMemo will highlight your read-point and you will be able to resume reading from the point you last stopped reading the article. To go to your current read point, press F7. If you forget to set a read-point, SuperMemo will leave a read-point at the place of your last extract
  8. Go to the next article: After you finish reading a portion of one article, choose Learn or Next repetition to proceed with reading other articles. Those buttons are located at the bottom of the element window. If the selected text in the article is not empty, it is enough you press Enter to go to the next article (otherwise, Enter will add a new line in the article)
  9. In incremental reading, interrupted reading is a rule, not an exception! (see advantages above)
    With a dose of practice, you will quickly get accustomed to this not-so-natural state of affairs and learn to appreciate the power of incremental approach. Use the following criteria to decide when to stop reading the article:
  10. Once you complete reading the article, press Ctrl+Shift+Enter (or Learning : Done on the element menu). This will dismiss the article, i.e. remove it from the review process. Done will also delete the contents of the processed article (without deleting the extracted material) and delete childless articles (i.e. articles that did not provide interesting extract or whose extracts have been processed and moved to various categories). Using Done will greatly reduce the size your collection and eliminate "dead hits" when searching through your collection
  11. If you have an impression that the article is difficult and you would like to read some fragments later, extract those fragments with Reading : Schedule extract and provide a review interval that will reflect the time you believe you will be better equipped to understand the extracted fragment

Warning! Some texts rich in pictures and tables may be handled with difficulty by SuperMemo. It may be very useful to learn to use HTML filters (press F6). See: Problems with HTML. Some of those problems stem from bugs in Internet Explorer that SuperMemo employs to display and edit HTML. This particularly refers to Internet Explorer 6. It is therefore highly recommended you install Internet Explorer 7 to make your life easier. With a dose of patience, you will learn to work around these problems.

Skill 3: Extracting fragments, questions and answers

In the course of traditional reading, we often mark important paragraphs with a highlighter pen. In SuperMemo, those paragraphs should be extracted as separate mini-articles (elements) that will later be used to refresh your memory. Each extracted paragraph or section becomes a new element that will be subject to the same reading algorithm as discussed above. Extract important fragments and single sentences with Remember extract (Alt+X). Remember to add necessary context to make sure that the extracted fragment does not become meaningless with time. You can use the Reference options on the component menu (esp. Alt+Q) to easily add context to your extracts. For example, select the title of the source article and press Alt+T (Reference : Title). This way, each extract will be marked by the title of the source article. If you fail to provide the context, you can use the reference link button on the element toolbar to jump to the source article from which the extract had been produced.

Incremental reading in SuperMemo: learning about Henipavirus from Wikipedia

In the picture (click to enlarge): typical snapshot of incremental reading. While learning about henipavirus, the student extracts the fragment saying that "flying foxes are unaffected by Hendra virus infection". The extracted fragment will inherit illustrations placed on the right, as well as article references (not visible in the picture). The selected 'n' at the end of the extracted fragment is a read-point. The student can move on to reading another article by pressing Enter. The pictures on the right are stored locally in the Image Registry (on the user's hard disk) and can be reused to illustrate other articles or questions.

SuperMemo will show you that extracting important fragments and reviewing them at later time will have an excellent impact on your ability to remember and benefit from your learning material. However, it will also show that once the time between reviews increases beyond 200-300 days, reading and re-reading (passive review) will often result in insufficient recall of the material. For this reason, sooner or later, you will need to use Remember cloze by pressing Alt+Z (or clicking the blue Z icon on the Read toolbar or on the element toolbar). Remember cloze will help you convert a sentence into a series of questions with answers. This way you will move from passive review to active recall. You do not need to wait until a paragraph or a sentence become hard to recall in passive review. For your most important material, you can create cloze items immediately after finding a piece of information that you need to remember well.  

Generating a cloze deletion in incremental reading in SuperMemo

In the picture (click to enlarge): the sentence extracted during incremental reading (see the previous picture) is converted into a cloze deletion. (i.e. a type question-answer pair). Pictures from the original extract have been inherited (on the right). The picture of the bat embedded in the question remains remote (i.e. it is located on the Internet, not on the user's hard disk). The student has just graded his answer as Good and is informed that he will be tested again on the same question on Oct 20, 2006. Pink texts at the bottom of the question are references generated automatically when importing an article from Wikipedia.

While converting extracts into questions and answers, you should make sure your questions are simple, clear and carrying the relevant context. For example, if you have extracted the following fragment from your reading about the history of the Internet:

The Internet was started in 1969 under a contract let by the Advanced Research Projects Agency (ARPA) which connected four major computers at universities in the southwestern US (UCLA, Stanford Research Institute, UCSB, and the University of Utah)

you may discover than when review intervals become long enough, you may not actually be able to recall the name of the ARPA agency or even forget the year in which the Internet started. You can then select an important keyword, e.g. 1969, and use Remember cloze to produce the following question-answer pair:

Question: The Internet was started in [...] under a contract let by the Advanced Research Projects Agency (ARPA) which connected four major computers at universities in the southwestern US (UCLA, Stanford Research Institute, UCSB, and the University of Utah)
Answer: 1969

In the course of learning, you will yet need to polish the above item by manual editing it to a more compact and understandable form:

Question: The Internet was started in [...](year) under a contract let by the ARPA agency
Answer: 1969

Or better yet:

Question: The Internet was started in [...](year)
Answer: 1969

As for the precious information "lost" during the editing, it can (but does not have to) be learned independently with separate questions generated by Remember cloze.

The mini-editing of questions presented above added the following benefits to the newly created question-answer pair:

  1. clearer purpose of the question: the fact that the question is about the year in which the Internet began is emphasized by using the red-colored (year) hint
  2. brevity: by removing superfluous information, you will not waste time on information that is not likely to be remembered (only actively recalled material will be remembered for years). You will answer the question and never focus on which universities were originally connected by the early Internet. If you believe this information is important, you will use the original extract to produce more cloze items that will focus solely on the universities in question by naming them in the answer field (if you disagree, read: 20 rules of formulating knowledge
  3. understandability: "the ARPA agency" phrase may defy grammar rules you have learned in primary school, but it is by far more understandable than just the ARPA. In SuperMemo, understandability is more important than stiff rules of grammar or spelling!


Skill 4: Repetition and review

SuperMemo is based on repetition. You make repetitions of the learned material in order to ensure that your knowledge retention (i.e. your ability to recall facts) reaches the desired level (usually 95-98%).

In SuperMemo, incrementally processed articles will also be subject to repetition. We will often use the more intuitive term review in reference to incrementally processed material; after all, when you resume reading an article after a certain interval of time, you are not actually repeating anything. You are simply reading new sections of the same material and extracting newly acquired wisdom into separate elements with Alt+X (i.e. Remember extract).

The algorithms that determine the timing of (1) repetitions of question-and-answer material and (2) reviewing reading material are analogous but not identical. Most importantly, all repetitions and article presentations happen in increasing intervals by default. In incremental reading, you will see a constant inflow of new articles into your collection. Unprocessed material will need to compete with the newly imported material. Increasing review intervals make sure that your old material fades into lower priority if it is not processed quickly. The speed of processing will depend on the availability of your time and the value of the material itself. Articles that are boring, badly written, less important for your work or growth, will receive smaller portions of your attention and may go into long review intervals before you even manage to pass a fraction of the text. That is an inevitable side effect of a voluminous flow of new information into your collection and into your memory. However, intervals and priorities can easily be adjusted. If the priorities change, you can modify the way you process important articles. At review time, you can either read the entire article without interruption, or revert it to a shorter interval. You can manually change its priority (e.g. with Alt+P). You can also use search tools (e.g. Ctrl+F) to locate more articles on the subject that you feel you have neglected. You can reprioritize a bunch of articles by changing their priority. You can shorten their interval or review them all when needed (see subset operations in the browser).

The algorithm for reviewing questions and answers (e.g. cloze deletions) is quite complex and limits your influence on the timing of repetitions (see: SuperMemo Algorithm). This is to ensure a high level of knowledge retention, which might be compromised by manual intervention.

However, the algorithm for determining inter-review intervals in incremental reading is much simpler and is entirely under your control. Each article receives a specific priority. The priority determines which articles are reviewed first and which can be postponed in case you run out of time. Each article is also assigned a number called the A-Factor that determines how much intervals increase between subsequent reviews. For example, if A-Factor is 2, review intervals will double with each review. Priority and A-Factors are set automatically, but you can change them manually at any time. Both are determined heuristically on the basis of the length of the text, the way it is processed, the way it is postponed or advanced, and by many other factors. Long texts will receive low A-Factors (e.g. 1.1), while short extracts will receive higher A-Factors (e.g. 1.8). Manually typed texts have higher priority and lower A-Factors than automatically imported texts. You can change the priority and A-Factor of an article by pressing Alt+P. You can also use Ctrl+Shift+Up and Ctrl+Shift+Down to increase or decrease element's priority. A-Factors associated with items cannot be changed by the user, as they are a reflection of item difficulty that determines the length of optimum inter-repetition intervals (see: forgetting index).

You can control the timing of article review by manually adjusting inter-review intervals. Use Ctrl+J (Reschedule) or Ctrl+Shift+R (Execute repetition) to determine the date of the next review. Ctrl+J will increment the current interval, while Ctrl+Shift+R will first execute a repetition and then set the new interval. For example, if your current interval is 100 and you specify the value of 3 in Reschedule, your new interval will be 103 and the last repetition date will not change. If you do the same with Execute repetition, your new interval will be 3 and the last repetition date will be set to today.

In heavily overloaded incremental reading, you will often want to learn only a portion of material related to a given subject. For that purpose, read about the priceless concept of subset learning.

Skill 5: Handling large volumes of knowledge

In incremental reading, you may quickly import and produce more learning material than you can effectively process. To make sure that your learning does not suffer from overload, you should use the priority queue. Using Alt+P (Learning : Priority : Modify on the element menu), you can set each element's priority from 0% to 100%. Remember that 0% corresponds with high priority while 100% with low priority. By default, your outstanding repetitions will be auto-sorted from high to low priority. This way, if you fail to complete your daily load of learning, it will only be the lower priority material that will suffer. Also by default, at the beginning of your working day (i.e. at your first run of SuperMemo), your outstanding material from previous days will be be auto-postponed (again with high-priority material being least affected).

Read an article about the priority queue to learn more about (1) manual sorting of elements, (2) defining sorting criteria, (3) turning off auto-sort and auto-postpone, etc.

Read about the postpone dialog to learn about defining postpone criteria.  

To effectively work with material belonging to different subjects of different priority, you might also want to study the following:

  1. using templates (providing different branches with a different look)
  2. using categories (easily adding knowledge to different branches of the knowledge tree)
  3. flow of knowledge in SuperMemo (summary of skills related to the flow of knowledge between branches and knowledge pools such as memorized, dismissed, processed, pending, extracts, articles, etc.)

Optional: History of incremental reading

Incremental reading might be as important for SuperMemo as the original repetition spacing algorithm. Incremental reading eliminates a number of bottlenecks that limit the first stage of learning: knowledge acquisition.

Older SuperMemos: In the years 1987-1998, users of SuperMemo had only two alternatives in the area of collecting learning material for learning with SuperMemo: (1) type it in and formulate it manually or (2) obtain ready-made learning material from colleagues, SuperMemo Library, etc. The only way SuperMemo supported learning from electronic sources was via Copy and Paste

SuperMemo 99 made the first step towards efficient reading of electronic articles by introducing reading lists and the first primitive reading tools: extracts and clozes. Reading lists are prioritized lists of articles to read. Extracts make it possible to split larger articles into smaller portions. Clozes makes it possible to convert short sentences into question-answer format by means of cloze deletions

SuperMemo 2000 greatly increased the efficiency of reading by introducing the concept of incremental reading. Incremental reading makes it possible to simultaneously read dozens of articles. Each article is read in small increments fully controlled and prioritized by the user and/or the default learning process. Components of incremental reading introduced in SuperMemo 2000: new A-Factor-based topic repetition scheme (i.e. learning algorithm), read points, formatting in extracts and in clozes (SuperMemo 99 would ignore formatting), text highlights, source article link, reading toolbar, subset learning, subset postpone, and support for longer articles (SuperMemo 99 was limited to 64K articles)

SuperMemo 2002 brought incremental reading to a new level. For SuperMemo 2002, incremental reading become the primary learning mode for middle-level and advanced students. SuperMemo 2002 introduced HTML-based incremental reading. For the first time, the user would see little difference between the material in his web browser and in SuperMemo. Other new features introduced by SuperMemo 2002: wholesale learning material import from Internet Explorer, mid-interval repetitions that make it possible to review portions of material without damage to the learning process (Algorithm SM-11), search-based learning (i.e. subset learning in which the subset is defined by advanced search tools), dynamically modified A-Factors that fine-tune the priorities without user intervention, postpone wizard that makes reading lists obsolete, separate topic/item statistics and new incremental reading progress statistics, reference labeling, and more

SuperMemo 2004 has been developed solely with the view to perfecting the tools used in incremental reading. The data collected from months of actual incremental reading have been instrumental to enhancing the algorithm and the tools. Fine tuning of the modification of topic A-Factors enhances the optimization of new material review in a heavily overloaded process. New tools include: rich statistics for monitoring and optimizing the learning process, tools for handling excessive delays in review, browsing sources of extracts and clozes, one-key reference labeling, proliferating remote images, easy integration of remote images, and more

SuperMemo 2006 makes a major step in rationalizing the overload of the learning material in incremental reading by introducing the priority queue. It makes it easier to import articles from the Internet (esp. from Wikipedia). It simplifies importing, arranging, compressing, converting, zooming and trimming pictures. SuperMemo 2006 can now pick any folder on your hard disk and convert all your file archives into material that can be processed incrementally (e.g. article archives, picture archives, family albums, movie clips, documentation files, or assorted archives). SuperMemo 2006 also makes it simple to do one-key searches and import of auxiliary learning material on the web with customizable tools (e.g. Google, encyclopedias, dictionaries, picture archives, etc.)