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Contents : Overviews
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 random and unpredictable sequences, you will dramatically affect association of ideas and 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
  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 found 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 other articles may be delayed transparently, i.e. not by stressful procrastination but by a sheer competition with other pieces of information on a strictly prioritized basis
  6. Attention. Incremental reading widely stretches the span of human 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 this article, this subject or reading anything on a given day. 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. Those measures dramatically increase your attention and the fun factor of reading and learning. 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 repetition process of well-formulated items, you memory will often have already been established in a close to the optimum context. This comes from the need to extract a given piece of information from a larger body of knowledge that provides your items with the 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
  8. Prioritization: improved flow of knowledge as a result of more accurate prioritization of material. For example, reading lists in SuperMemo 99 required assigning Value to each article. Estimations of Value could be highly inaccurate. An interesting material that would receive a low Value might indefinitely wait in the queue for processing. Incremental reading allows of on-the-fly prioritization. It also provides tools that help you upgrade or degrade the priority of articles depending on the value of individual pieces of extracted information
  9. Fun. Maslov's hierarchy of needs and further research in psychology indicate that at a certain level of human development, 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 (e.g. in struggling with limitations of Internet Explorer as encapsulated by SuperMemo). 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.
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 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 Ctrl+J to specify the first review interval. For example: one day for high priority material or 30 days for low priority material (Ctrl+J is equivalent to Learning : Reschedule on the element menu)


Skill 2: Reading articles

You could precede reading articles with conveniently locating the Read toolbar on your screen. Choose Window : Toolbars : Read, place the toolbar in a convenient place on the screen and press Ctrl+Shift+F5 (to save the chosen layout as your default layout). If you do not see the Window menu read about levels.

This is the Read toolbar:

This is a simplified algorithm for reading articles:

  1. Import an article as explained earlier or bring up a previously imported article with Learn
  2. Click the article to make sure you enter the editing mode in which you can modify text, select fragments, etc.
  3. Start reading the article from the top
  4. If you encounter an interesting fragment, select the fragment 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 adjust the first interval after which the extract review will take place, choose Reading : Schedule extract instead of Remember extract (checked T icon on the Read toolbar) 
  5. If you read a fragment that does not seem important, delete it or select it and choose Reading : Ignore on the component menu (or click the stop-sign icon). Selecting Ignore will mark the fragment with ignore font
  6. 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 fragments retains all contextual clues: 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 proliferate automatically to all extracts of a given article
  7. 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 the read-point, SuperMemo will leave a read-point at the place of your last extract
  8. After you finish reading a portion of one article , choose Learn or Next repetition to proceed with review of other articles
  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 childless articles (i.e. articles that did not provide interesting extract or whose extracts have been processed and moved to target categories). Using Done will dramatically reduce the size your collection and eliminate "dead hits" when searching 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. 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 elements that will later be used to refresh your memory. Each extracted paragraph or section becomes a mini-article 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 clues to make sure 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.

SuperMemo will show you that extracting important fragments and reviewing them at later time will have an excellent impact on your ability to benefit from the processed material at later times. However, it will also show that once the review intervals grow beyond 200-300 days, passive review will often become insufficient. At that time you will need to use Remember cloze by pressing Alt+Z (or click the blue Z icon on the Read toolbar or on the element toolbar). This option will help you convert a sentence into a series of items in the question-and-answer form. Naturally, for important material, you can create cloze items as soon as you find an important sentence that you need to remember. You do not need to wait until the sentence becomes hard to recall in passive review. 

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 item:

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

This mini-editing added the following benefits to the above question-answer item:

  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 reaches the desired level (usually 95-98%).

In SuperMemo, your incrementally processed articles will also be subject to repetitions. 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 used to make (1) standard repetitions of question-and-answer material and (2) reviewing reading material are similar. Most importantly, all repetitions and article presentations happen in increasing intervals. In incremental reading, you will constantly see inflow of new material to your collection. Unprocessed material will need to compete with the newly imported material. Increasing review intervals makes sure that your old material fades into lower priority if it is not processed quickly. Naturally, 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 your memory). However, intervals and priorities can easily be adjusted. If the priorities change, you can modify the way you process important articles. Upon the next review you can read the whole article or revert it to a shorter interval. You can even use search tools (Ctrl+F) to locate more articles on the subject you feel you have neglected and reprioritize these as well (e.g. with Learning : Advance on the browser subset operations menu).

The algorithm for repeating questions and answers (e.g. cloze deletions) is quite complex and you do not have much influence on the timing of repetitions (see: SuperMemo Algorithm). This stems from the need to keep a high level of knowledge retention, which can 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 number called A-Factor that determines how much intervals increase between subsequent reviews. For example, if A-Factor=2, review intervals will double after each review. A-Factors 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 more. 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 lower A-Factors than automatically imported texts. You can change the value of A-Factor associated with a given article by choosing Ctrl+Shift+P. You can also use Ctrl+Shift+Up and Ctrl+Shift+Down to increase or decrease element's priority (as reflected by the A-Factor). A-Factors associated with items cannot be changed by the user (see: forgetting index).

You can also 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 to the selected value. In other words, 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 priceless subset learning

Skill 5: Handling large volumes of knowledge

In incremental reading, your work with SuperMemo will freely combine and mix (1) reading with (2) standard repetitions. Randomizing the sequence of repetitions should be encouraged. With more material in the process than you can handle daily, only random coverage of the material will provide you with a true sense of your progress. You can randomize your daily portion of repetitions with Learn : Random : Randomize repetitions (Ctrl+Shift+F11).

By using Randomize repetitions, your repetitions will not favor more accurate processing of material based on the length of the interval, element type (e.g. articles, extracts, question-and-answer items, etc.), contents (i.e. branch of the knowledge tree) or degree of processing. Random repetitions will help you better understand possible negative trends such as excessive inflow of new material, lower retention (mostly as a result of frequent rescheduling), poor formulation of newly created cloze deletions, low quality or applicability of the acquired knowledge, excessive emphasis on certain subject at the cost of other subjects, etc.

Your hunger for new knowledge may quickly result in a substantial overflow of the new material at the cost of the quality of knowledge and and the cost of retention. For this reasons you may, but do not have to, decide to execute your repetitions in the following stages:

  1. random and indiscriminate review and repetition of all outstanding material
  2. random repetitions with the exclusion of topics (articles, and unprocessed extracts). With the help of Postpone you can postpone all topics or all topics except the most important articles as indicated by interval, A-Factor, etc. You can, for example, use Learn : Postpone : Topics for that purpose
  3. random repetition of all material with the exclusion of newly created and not fully processed questions-and-answers (mostly cloze deletions) (see how)
  4. random repetition of top-priority question-and-answer material with selective delay of repetitions in branches of knowledge that are less important

Postpone makes it possible to reschedule only a subset of repetitions. For example you can opt to delay repetitions in subsets such as:

Postpone uses a number called a delay factor that is used to increase intervals of outstanding repetitions. Intervals are simply multiplied by the delay factor. For example, if you choose to Postpone with the delay factor of 1.1, all intervals will be multiplied by 1.1 and will increase by 10%. Postpone will always increase intervals by no less than one day from the present day. This way, all items on which Postpone is executed fall out of the outstanding subset. 

You will mainly execute Postpone with Ctrl+Alt+P in three ways:

  1. in the contents window: if you want to postpone a given branch of knowledge (e.g. new items)
  2. in the browser: if you want to postpone any subset of items that you can generate with browser operations (see: Using subsets)

  3. in the element window: if you want to postpone any ancestor branch to which the currently repeated element belongs

Here are some typical ways in which you will execute Postpone:

If you would like to make your repetitions using the above suggestions, you should add all your new material to a selected branch, and transfer individual items to target categories such as sociology, psychology, history, etc., only then when you are sure that these items have received their final wording and meet your stringent quality criteria. As a rule, you should not ever use Postpone on your mission critical knowledge. If you do so, you are bound to miss your retention targets! With time, Postpone will always increase the measured forgetting index. It should only be used to eliminate an excess of lower priority material. You will mostly want do postpone half-processed material, low priority branches (e.g. Private, Hobbies, etc.), and less important questions. 

To efficiently 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. It eliminates a number of bottlenecks to learning at its first stage: 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 extracts and clozes (SuperMemo 99 would ignore formatting), text highlight and ignore, source article link, reading toolbar, branch and browser learning, branch and browser postpone, and support for longer articles (SuperMemo 99 imposed 64K limit on 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