|New article by Dr. Piotr Wozniak: The true history of spaced repetition|
|Devouring knowledge||Dr Piotr
Dec 2000 (revised June 2004)
This article will tell you
how to maximize the speed of learning.
|Marvin Minsky: Our cultures don't encourage us to think much about learning. Instead we regard it as something that just happens to us. But learning must itself consist of sets of skills we grow ourselves; we start with only some of them and slowly grow the rest. Why don't more people keep on learning more and better learning skills? Because it's not rewarded right away, its payoff has a long delay|
This article summarizes my 20-year-long effort in developing techniques and technologies that assist human learning. It should help you quickly convert your learning into a rationally controlled and conscious process. I believe, it describes the tools that collectively account for the fastest learning approach in existence. If knowledge is important to you, this article should help you optimize your path towards your goals. Among others, we will discuss two concepts that can have a dramatic effect on learning:
- spaced repetition: a technique that ensures nearly perfect recall with minimum possible investment of time via computing optimum inter-repetition intervals
- incremental reading: a fast reading technique derived from spaced repetition that makes it possible to read thousands of articles at the same time without getting lost
This short insert paints the
picture of knowledge in the epicenter of progress. If you need no convincing as
central role of knowledge in our lives, jump directly to Knowledge
Acquisition - stages of learning that can be optimized
There are five main areas where the learning process can be enhanced. All these areas will be discussed in this article:
Access to knowledge
The Internet is an excellent source of knowledge. Its quality and role will for long continue increasing exponentially as more and more people appreciate its potential and contribute to its growth. There are still many complementary sources of information that compete successfully with the Internet. However, it is only a question of time before you will be safely able to rely on the Internet as your sole source of information.
The three main factors that limit the value of the Internet as the source of information today:
Despite the Internet's limitations, you can safely commit yourself today to making the net your chief source of knowledge in your quest for new knowledge in nearly all areas of well-rounded self-instruction. The abundance of free encyclopedias, journals, dictionaries, databases, stand-alone articles and thematic websites is mind-boggling.
All you need for the purpose of knowledge access is a web browser and basic net-searching skills combined with an understanding of the power of individual search engines such as www.google.com
Throughout this article, I will try to demonstrate that you will need a tool for efficient prioritizing and reviewing information: SuperMemo 2004 for Windows. The true power and importance of SuperMemo comes from ensuring high retention of knowledge. SuperMemo 2004 will also help you greatly increase the quality of reading by means of a technique called: incremental reading. In addition to its main strengths, SuperMemo can also assist in the field of knowledge access. You will certainly face the need to fill the gaps in your knowledge in many more areas than your time permits or your memory makes possible. You can ask SuperMemo to help you scrupulously note down and prioritize all areas of knowledge that need an enhancement!
The extent of global knowledge resources can be measured in terabytes. One terabyte is a thousand gigabytes, while one gigabyte is a rough equivalent of the Encyclopaedia Britannica whose 44 million words would most likely all fit your today's hard disk space. The US Library of Congress is estimated to amount to 25 terabytes of knowledge. Human DNA code kept at Celera takes 80 terabytes. At the same time, the so-called deep web (year 2000) may encompass as much as 7,500 terabytes (deep web includes the static web extended by dynamic information retrievable from web databases). It will take only three years from today to produce more data than in the whole of human history (say researchers at the University of California).
Only a fraction of those resources can be mastered by an individual in a single human lifetime. Even a single copy of the Encyclopaedia Britannica goes in detail far beyond what a single human being can encompass in a lifetime! The actual speed of learning and lifetime learning limits can be measured with SuperMemo (see: Theoretical aspects of SuperMemo).
The microscopic capacity of the human brain has not prevented it from building the present civilization as we know it. The human power comes from:
This article will show you how to prevent forgetting. However, forgetting plays an important role in our lives. It runs a valuable garbage collection on knowledge we acquire daily. If the power of forgetting is taken away, your responsibilities in the area of selecting knowledge increase manifold!
|SuperMemo will help you eliminate forgetting! At the same time, it will increase your responsibility for selecting knowledge that is truly important and applicable. If used without care and attention, SuperMemo may actually waste your time by helping you remember reels of garbage trivia|
A piece of information that occupies just several bytes of your hard disk may carry a relative value that my translate to a net gain of millions of dollars as well as a net loss of millions of dollars. It may also carry no value whatsoever. For example, a sentence written in French "SuperMemo vous aide à mémoriser et apprendre diverses informations comme une langue, des chiffres, etc." may be of nearly zero value for someone who does not know French. At the same time, an item related to a Heimlich maneuver can save the life of a family member. We know that the expected payoff equals the value of the payoff multiplied by its probability; therefore, the low probability of a family member choking and the probability of actual successful application of the maneuver make the value of "Heimlich item" a fraction of the value of the human life. At the same time, even minor errors in medical knowledge of a physician can actually cost somebody's life and carry substantial negative value!
|Frequently, you will find more
benefit in memorizing the three best things you have learnt today than
in memorizing a whole monothematic article to the last detail!
It is possible to store the mind with a million facts and still be entirely uneducated (Alec Bourne)
I have mentioned earlier that SuperMemo 2004 can help you prioritize knowledge areas and topics that you want to study. In a similar way, SuperMemo 2004 will help you prioritize articles you locate on the net and decide to study in detail.
Importing articles to SuperMemo 2004
To import an important article to SuperMemo, follow these steps:
Traditional linear reading is highly inefficient. This comes from the fact that various pieces of the text are of various importance. Some should be skipped. Others should be read in the first order of priority. Old-fashioned books are quickly being replaced with hypertext. Hypertext will help you quickly jump to information that is the most important at any given moment. Hypertext requires a different style of writing. After all, all texts will live by the assumption that there has been some introductory section read before. The texts become context-independent, and all difficult terms and concepts are explained solely with additional hyperlinks. As the world wide web helped delinearize the global resources of information, SuperMemo 2004 can help you delinearize your reading of whatever linear material you decide to import to SuperMemo. While reading with SuperMemo, you will see a linear text as a sequence of sections subdivided into paragraphs and individual sentences. SuperMemo will help you provide a separate and independent processing for each section, paragraph or sentence. Here are some typical actions you will execute on individual sections, paragraphs or sentences. Most typically you will decide one of the following:
read and remember - you can read a paragraph and schedule it for a future review. The timing of the review will depend on the paragraph's priority
skip to read later - you can mark a paragraph as worth reading later. The moment in which the paragraph will come back for reading will depend on the paragraph's priority.
skip for ever - you can mark a paragraph as (1) not worth reading, or as (2) read and not worth remembering
In SuperMemo, all material worth remembering will be scheduled for review in the future. This is necessary to ensure you do not forget what you have learned. At the same time, all material that has not been read but is classified as worth reading will also be scheduled for reading in the future. In SuperMemo, you will constantly face a serial process of reading, review, and repetition that will make sure that your work with the program is challenging, interesting and leaves permanent traces in your memory.
|Reading with SuperMemo 2004
When reading an article in SuperMemo 2004, you will process individual paragraphs or sentences with commands available from the Reading menu available with a right-click over the selected text. For fastest processing, these commands are also available on the reading toolbar:
You will begin reading an article in one of these circumstances:
Here are the typical actions you will perform on individual sections, paragraphs and sentences:
If you believe the whole article should be skipped, you can do the following:
In SuperMemo, all imported articles will evolve. This evolution will ensure maximum comprehension and retention of knowledge. Initially the articles are split into sections and paragraphs. Those sections and paragraphs are later subject to regular review and further evolution. Individual paragraphs get enriched with context clues, reference labels, and converted to individual sentences. Individual sentences convey ideas which you want to remember. These ideas come back for review at increasing intervals. Initially, the ideas come back every couple of days, later after months and years. However, passively processed ideas in the form of sentences rarely leave a durable trace in your memory even if they are reviewed regularly. Very often, as soon as after 2-3 months, you will notice that at review time, you actually do not seem able to recall that you have ever had a given sentence in your collection. You will quickly discover that you need active recall in order to remember. Active recall is a process in which you must answer questions. For example, you may be presented with a picture of Charles Darwin and be asked to recognize his face. In the long run, you need to replace passive review with active recall. Otherwise, your memory of the fact will not be permanently consolidated.
The fastest way of converting simple sentences into active recall material is to use a cloze deletion technique (nb: cloze is the correct spelling; please do not report an orthographic error!). In the cloze deletion technique, you convert simple declarative sentences like:
WW1 was precipitated by the assassination of Archduke Francis Ferdinand of Austria-Hungary by a Serbian nationalist in 1914
into question-answer pairs that can be used in actively stimulating your memory for best recall:
Question: WW1 was precipitated by the assassination of Archduke Francis Ferdinand of [...](country/empire) by a Serbian nationalist in 1914
Question: WW1 was precipitated by the assassination of Archduke Francis Ferdinand of Austria-Hungary by a Serbian nationalist in [...](year)
Question: [...](war) was precipitated by the assassination of Archduke Francis Ferdinand of Austria-Hungary by a Serbian nationalist in 1914
Active recall in SuperMemo 2004
To convert a sentence to a cloze deletion in SuperMemo 2004, select the appropriate keyword in the sentence (e.g. Austria-Hungary, 1914, WW1, etc.) and press Ctrl+Z. You can also choose Reading : Remember cloze available with a right click over the selected text, or click the blue Z-icon on the Read toolbar.
If you would like to immediately reedit the newly created cloze deletion, choose button on the element toolbar or press Alt+Left. This will make it possible to add context clues, shorten the text, improve the wording, etc.
Tip! Try to avoid using cloze deletion tools on conglomerate paragraphs. Your cloze deletions should be as simple as possible. Consequently, simplifying the parent paragraph to a simple statement will produce simple clozes that will require little processing. If you use Remember cloze on a longer multi-sentence paragraph, you will have to put extra effort on simplifying the resulting items. All cloze deletions should be short enough to ensure you read them entirely at repetition time. Otherwise, your brain will tend to "deduce" the answer from non-semantic clues. This will defeat the purpose of learning!
The active recall issue in representing knowledge is just a tip of the iceberg. You will need to master quite a number of skills that will ensure your knowledge is:
easy to remember
quick to process
You will hone those skills gradually in time. Your own mistakes will provide the best material for improvement. You will find more details in: 20 rules of formulating knowledge in learning
Forgetting has been the number one problem in learning for ages. All capable students know that it is not really hard to cram hundreds of pages of material before an exam. But a great deal of the learned knowledge is gone just 3-4 days later (esp. after an exhaustive all-nighter). 50% of the quickly crammed knowledge evaporates within a week or two. After a year or so, nearly all material is forgotten unless reviewed. It is easy to notice that the repetition is the key to remembering in the long run. Repetitio mater memoriae may date back to Horace (65-8 BC).
In SuperMemo, review of the learned material is in the center of the learning method. The review algorithm has started the whole concept of SuperMemo in the early 1980s and the first software implementation of SuperMemo in 1987 was based solely on repetitions of simple questions and answers.
SuperMemo makes it possible to remember, by default, 95% of the learned material (see: General principles of SuperMemo). You can program this retention level to fall between 90-99%. You can also determine the retention individually for each of the pieces of information subject to review. You can also use tools that will make it possible to substantially increase the flow of information into SuperMemo at the cost of retention.
|With SuperMemo, you can nearly eliminate the problem of forgetting! However, the cost of remembering is still substantial. SuperMemo protects your memories from the spontaneous process of forgetting and puts them in your own hands. Your persistence and conscious choices will determine what you remember and what you decide to give up to forgetting|
|Remembering with SuperMemo 2004
All material introduced to SuperMemo 2004 will be subject to review. This is all you need to remember:
You will often introduce to SuperMemo more material than you are able to review. You will therefore also need to consider the following:
Life cycle of knowledge
Knowledge stored in SuperMemo will gradually be transformed and reformulated. This will also reflect changes to the corresponding knowledge in your memory. Three main principles will underlie the evolution of knowledge in SuperMemo:
decrease in complexity - articles will be converted into sets of paragraphs. Paragraphs will be dismantled into sets of independent sentences and statements. Sentences will be shortened to maximize the contents-vs-wording ratio, etc.
active recall - all pieces of information will ultimately be converted into active recall material such as question-answer pairs, cloze deletions, picture recognition tests, sound recognition tests, etc.
incrementalism - all changes will take place gradually in proportion to available time, with respect to your selected material priority, and in line with the gradually increasing strength of memory traces
The core of SuperMemo is review and repetition. Changes to individual pieces of knowledge will take place in steps upon successive reviews. Here are exemplary steps that show a complete evolution of a single article into a finished item based on active recall:
Imagine that you find an article on the net, e.g. The criticism of global capitalism, and you decide to read it and remember it for ever
You import the article to SuperMemo
You read the article (e.g. once it tops your reading list or once its turn comes up in incremental reading)
While reading, you extract most important paragraphs. One of these, let us say, refers to Kuznets hypothesis
The extracted paragraphs will assume a separate life in SuperMemo and will be scheduled for separate review, i.e. independent of the review of the parent article. The extracted paragraphs in the parent article will be marked as processed. Once all paragraphs in the parent article are processed, you will terminate the review of the parent article and keep on reviewing only its components (e.g. selected paragraphs)
Upon the first review, usually after a few days, you read the extracted paragraph again and analyze it as to how it should be processed further. You may decide to postpone it, remove it from the learning process, shorten it or extract the most important sentences that you want to remember
If you decide to extract a single statement in reference to Kuznets hypothesis it will again be marked as processed in the original extract and will assume a separate review cycle in SuperMemo
Upon the first review of the extracted sentence, you make further decisions as to its further life in SuperMemo. Let us say, this is the wording of the Kuznets sentence: Acc to Kuznets hypothesis, growth (from the low income levels associated with predominantly agrarian societies) would first lead to an increase, and then to a decrease in income inequality
In order to capture the essence, you would probably decide to shorten the above sentence to the following form: Acc to Kuznets hypothesis, growth would first lead to an increase, and then to a decrease in income inequality
At the same time, other parts of the same parent article might establish a memory trace that would say that Kuznets hypothesis has been based on relatively weak empirical data. Moreover, recent research clearly indicates that the hypothesis is false (growth actually seems to equally benefit both the poor and the rich). You could then enhance the extract with words controversial or even recently falsified. For example, Recently falsified Kuznets hypothesis claimed that growth would first lead to an increase, and then to a decrease in income inequality
Upon the next review of the same sentence, you may decide to convert it into a number of cloze deletions. This conversion will be incremental, i.e. you may decide to first create a cloze deletion asking about the name of the controversial hypothesis and only later ask about its actual meaning (the meaning is relatively easier to remember and shall survive longer in your memory without active recall). Your cloze deletion could then look like this:
Question: Recently falsified [...](name) hypothesis claimed that growth would first lead to an increase, and then to a decrease in income inequality
This cloze deletion would again assume a separate life from the original sentence in which the keyword Kuznets will again be marked as processed. This is the original Kuznets sentence with one keyword marked as processed: Recently falsified Kuznets hypothesis claimed that growth would first lead to an increase, and then to a decrease in income inequality
The same sentence will generate a few separate cloze deletions that will be processed independently. Upon the first review of the cloze deletion created in the previous point, you may decide to simplify it in accordance with the rules of formulating knowledge in learning:
Question: Recently falsified [...](name) hypothesis claimed that growth would first lead to an increase in income inequality
Upon the next review, you can, but you do not have to, convert the cloze deletion into a standard question-answer item:
Question: What is the name of the hypothesis that falsely claims that income inequality initially increases with growth?
Answer: Kuznets hypothesis
The above question-answer pair is probably as simple as it can only be. Certainly, it is simple enough to be relatively easy to remember. This item will be repeated in intervals determined by SuperMemo. You can decide how well you want to remember it. By default, it will be remembered with 95% probability of recall and require 5-15 repetitions in lifetime. The establishment of durable memory traces in your memory, completes the life cycle of this particular piece of knowledge. The only thing that remains is the memory-sustaining review in intervals ranging from months to years (as determined by SuperMemo)
Once you convert all important keywords from the Kuznets hypothesis into separate cloze deletions, you will remove the parenting paragraph from the review process. You will not longer passively review the original declarative hypothesis. You will continue repeating individual clozes and that will ensure your perfect recall of the hypothesis for as long as you deem necessary
To learn more about the life cycle of knowledge in SuperMemo read: Flow of knowledge in SuperMemo
If you stop reading an article and return to it after a month or so, you may find it hard to understand the text due to the fact that the part read earlier will have already been partly forgotten while it might have built a solid introduction needed for understanding the remaining sections of the article.
In SuperMemo, reading articles in small parts does not pose a problem. The parts read earlier enter the regular review process that ensures continual retention of all pivotal points. Even more, SuperMemo encourages reading in small parts. This makes it possible to read many articles at the same time, and portion the inflow of information into the learning process in proportion to priority and available time.
The process or reading many articles at the same time in small portions will later be called incremental reading.
Without SuperMemo, incremental reading would not be possible. This comes from the fact that only SuperMemo can ensure that you do not forget what you have read before. In other words, if you return to the same article in a week or in a few months, you will quickly recover the context and keep on reading as if you have read preceding parts just minutes earlier.
The advantages of incremental reading are numerous. They all are interdependent. Good retention enables incremental reading. This provides variety which eliminates boredom, enhances attention and affects creative associations. Good prioritization enhances the speed of reading without affecting comprehension, and that in turn, eliminates the stress of fast reading (worry of missing important pieces of information) and the stress of massive reading (worry of losing track of one or more articles).
Here is the list of the most prominent advantages of incremental reading:
knowledge structure and comprehension: Building knowledge in your brain is like assembling a jigsaw puzzle. Some pieces cannot be placed in the puzzle before the others. Some pieces capitalize on others. There is no point in memorizing facts about Higgs boson before you learn what a standard model is and that, in turn, should follow the general understanding of particle physics which itself requires some ABC of physics. In incremental reading, if you encounter texts related to Higgs boson you can manually delay it until the time you hope your Physics ABC will provide the ground for understanding. In traditional reading, you would just waste your time on reviewing Higgs boson material. Traditionally, your decision to skip the material would provide no definite way of coming back to material in the future. With incremental reading, you waste no time on reading material you do not understand. At the same time, you can safely skip portions of material and return to them in the future. You become the master of the conscious knowledge building process
attention: Human brain has an in-built limit on the attention span. We all get bored with things. This is often true even with interesting articles once they get too long. Millions of people do a daily channel zapping on TV. This absurd activity is driven precisely by the craving for dense action and information variety. A gripping movie goes "too slow" for a typical channel zapper. This is why he or she prefers to watch three movies at the same time (even though the plot of all will suffer). Incremental reading is a perfect remedy to the limited attention span. Once you sense any sign of boredom or distraction, you can jump to the next article with few negative side effects. Unlike in the case of channel zapping though, you won't miss a bit of information. Just the opposite, you will maximize attention per paragraph. Your attention to the same piece of information may depend on your mood, amount of prior reading, today's interest that may depend on the piece of news you heard on the morning radio, etc. With incremental reading, you can fit your best attention to each individual piece of reading
speed: Incremental reading will help you dramatically increase the speed of your first reading of a selected text. You can quickly jump from paragraph to paragraph, get the overall picture, mark fragments for later reading, mark fragments for detailed study, etc. You will be relieved of the greatest bottleneck of speed-reading: fear of missing important pieces of information. As soon as you suspect a quickly-reviewed paragraph may carry more importance than meets the eye, you can simply introduce it back into the review process (as opposed to backtracking and reading the paragraph again). Once you process the entire article, you can slowly digest it again from the very beginning in the incremental reading process. Incremental reading provides for speed-reading without detriment to comprehension
prioritization: There are always many more articles at hand than you can hope to read. Evaluating articles and prioritizing them is difficult because you cannot do a good evaluation without actually reading a part of the article in question. In incremental reading, you can read the introduction and then decide when to read the rest. If an article is extremely valuable or interesting, you can process it entirely at once. Other articles can slowly scramble through the learning process. Yet others may ultimately be deleted. The prioritization will continue while you are reading the article. If the evaluation of quality or content changes while reading, so will the reading-review schedule. Prioritization tools will ensure that important pieces of information will receive better processing. This is one of the most important things about incremental reading: efficient fishing for pieces of golden knowledge!
consolidation: Everything we learn must be reviewed from time to time in order to be remembered. If you read an article in intervals, you already begin the consolidation of memory which may save you lots of time. In traditional reading, you would need to read the whole article, and then to review the article later several times. With earlier releases of SuperMemo, you would need to read the whole article, and then only review the most important parts of the article in SuperMemo at intervals determined by the program. Now you can begin the consolidation-review cycle already during reading! By the time you convert parts of the material into clozes or question-answer items, you will already have it well consolidated. This pre-consolidation will often dramatically reduce the number of repetitions required before your material gets to be reviewed in long intervals of months and years
creativity: SuperMemo will throw at you various articles, paragraphs, statements and questions in a most unexpected order. You will be surprised to discover how this affects your creativity and helps you generate unexpected associations of ideas. This will also provide your brain with an entertaining form of mental training that will be highly appreciated in all forms of professions based on intellectual performance. Critics of incremental reading, who have never tried the method, are not convinced this argument is really tenable. You may be skeptical too. There is only one sure way to convince you: give incremental reading a good try! Try incremental reading for a month at times when your brain is in its peak shape. If the processed knowledge belongs to the areas that are critically important to you, so much the better. You may see your brain turn into a creative sparkler!
stresslessness: Once you know you can rely on SuperMemo in presenting review material for you, you can eliminate the stress and anxiety related to having too much to study or too much to read. You will probably not manage to read or learn all that you would hope for, but you will at least not lose sleep over planning and scheduling. SuperMemo is a promise of the best use of your potential. With this conviction, you can devote all your energy to comprehension and analysis of the learned material
consistency: If your material contains contradictory parts, your brain will alert you to this fact. In classical learning, you would often relearn new facts that would contradict earlier learned facts. Then you would relearn the older version again and this wasteful cycle might repeat more than once. In SuperMemo, the same process can take place; however, there will be two mechanisms that will prevent it. High degree of retention guaranteed by SuperMemo will often make it quite effortless to immediately spot the contradiction: Wait a minute! I have already learned this fact and the answer was different! Unfortunately, even SuperMemo isn't hermetic to contradiction (your retention actually never reaches 100%). The second mechanism will quickly produce the convergence of contradictory facts in time. If you, for example, learn two different answers to What is the size of human population?, say, 5.5 billion and 6 billion. You will naturally provide a wrong answer to one of these questions. Once you relearn it the new way, you will provide a wrong answer to the other question. Inter-repetition intervals for these two contradictory items will get shorter with each relearning cycle. The timing of repetitions of contradictory items will tend to converge. It is only a question of time when the red alert is raised by your brain. You will quickly resolve the difference and delete one of the items. Similar process will affect hazy or incompletely specified information. Your knowledge will grow in consistency with time
massive learning: Massive learning is the consequence of all advantages listed earlier. Incremental reading will run a river of knowledge through your memory. The speed of acquiring new information will surprise you. Even though human memory is painfully limited, you shall be able to read thousands of texts pertaining to different fields and quickly swell the size of your knowledge to your and others' benefit
enjoyability: Those who can compare the classic SuperMemo with incremental reading will testify that incremental reading is by far more enjoyable. Monotonous repetitions are here interspersed with reading and analyzing new material
|Incremental reading tools in
To learn more about incremental reading see: Incremental reading in SuperMemo 2004
SuperMemo is not yet equipped with tools to help you efficiently use your knowledge for good causes. It will boost your knowledge but ... you must be vigilant: Do not spend your time on gaining knowledge for the knowledge sake! Think applicability!
Luckily, as your knowledge grows, so does your ability to use it efficiently.
Enjoy your learning!