org-drill.el – flashcards and spaced repetition for org-mode

Table of Contents

General

Org-Drill is an extension for Org mode. Org-Drill uses a spaced repetition algorithm to conduct interactive "drill sessions", using org files as sources of facts to be memorised. Each topic is treated as a "flash card". The material to be remembered is presented to the student in random order. The student rates his or her recall of each item, and this information is used to schedule the item for later revision.

Each drill session can be restricted to topics in the current buffer (default), one or several files, all agenda files, or a subtree. A single topic can also be drilled.

Different "topic types" can be defined, which present their information to the student in different ways.

For more on the spaced repetition algorithm, and examples of other programs that use it, see:

Org-Drill comes bundled with Org mode, in the "contrib" directory. Org-Drill also has its own repository, which is updated more regularly than the bundled version. The repository is at:

http://bitbucket.org/eeeickythump/org-drill

Installation

The easiest way is to customise the variable 'org-modules' (M-x customize-variables RET org-modules) and make sure 'drill' is ticked. Org-drill will then be loaded when you restart Emacs or restart Org-mode.

For manual installation, put the following in your .emacs. You will also need to make sure that Org's "contrib/lisp" directory is in the emacs load-path.

(require 'org-drill)

Demonstration

Open the file spanish.org. Press M-x and run the function org-drill. Follow the prompts at the bottom of the screen.

When the drill finishes, you can look at spanish.org to get some idea of how drill topics are written.

Writing the questions

Org-Drill uses org mode topics as 'drill items'. To be used as a drill item, the topic must have a tag that matches the value of org-drill-question-tag. This is :drill: by default. Any other org topics will be ignored.

Drill items can have other drill items as children. When a drill item is being tested, the contents of any child drill items will be hidden.

You don't need to schedule the topics initially. Unscheduled items are considered to be 'new' and ready for memorisation.

How should 'drill topics' be structured? Any org topic is a legal drill topic – it will simply be shown with all subheadings collapsed, so that only the material beneath the main item heading is visible. After pressing a key, any hidden subheadings will be revealed, and you will be asked to rate your "recall" of the item.

This will be adequate for some items, but usually you will want to write items where you have more control over what information is hidden from the user for recall purposes. For this reason, some other card types are defined, including:

A note about comments: In org mode, comment lines start with '#'. The rest of the line is ignored by Org (apart from some special cases). You may sometimes want to put material in comments which you do not want to see when you are being tested on the item. For this reason, comments are always rendered invisible while items are being tested.

Simple topics

The simplest drill topic has no special structure. When such a topic is presented during a drill session, any subheadings are "collapsed" with their contents hidden. So, you could include the question as text beneath the main heading, and the answer within a subheading. For example:

* Item                                   :drill:
What is the capital city of Estonia?

** The Answer
Tallinn.

When this item is presented for review, the text beneath the main heading will be visible, but the contents of the subheading ("The Answer") will be hidden.

Cloze deletion

Cloze deletion can be used in any drill topic regardless of whether it is otherwise 'simple', or is one of the specialised topic types discussed below. To use cloze deletion, one or more parts of the body of the topic is marked as cloze text by surrounding it with single square brackets, [like so]. When the topic is presented for review, the text within square brackets will be obscured. The text is then revealed after the user presses a key. For example:

* Item                                   :drill:
The capital city of Estonia is [Tallinn].

During review, the user will see:

The capital city of Estonia is […].

When the user presses a key, the text "Tallinn" will become visible.

Clozed text hints

Clozed text can contain a "hint" about the answer. If the text surrounded by single square brackets contains a `|' character (vertical bar), all text after that character is treated as a hint. During testing, the hint text will be visible when the rest of the text is hidden, and invisible when the rest of the text is visible.

Example:

Type 1 hypersensitivity reactions are mediated by [immunoglobulin E|molecule]
and [mast cells|cell type].

Type 1 hypersensitivity reactions are mediated by [molecule…] and [cell type…].

Two-sided cards

The remaining topic types all use the topic property, DRILL_CARD_TYPE. This property tells org-drill which function to use to present the topic during review. If this property has the value twosided then the topic is treated as a "two sided card". When a two sided card is reviewed, one of the first two subheadings within the topic will be visible – all other subheadings will be hidden.

Two-sided cards are meant to emulate the type of flipcard where either side is useful as test material (for example, a card with a word in a foreign language on one side, and its translation on the other).

A two sided card can have more than 2 subheadings, but all subheadings after the first two are considered as "notes" and will always be hidden during topic review.

* Noun                                               :drill:
    :PROPERTIES:
    :DRILL_CARD_TYPE: twosided
    :END:

Translate this word.

** Spanish
la mujer

** English
the woman

** Example sentence
¿Quién fue esa mujer?
Who was that woman?

In this example, the user will be shown the main text – "Translate this word" – and either 'la mujer', or 'the woman', at random. The section 'Example sentence' will never be shown until after the user presses a key, because it is not one of the first two 'sides' of the topic.

Multi-sided cards

The multisided card type is similar to twosided, except that any subheading has a chance of being presented during the topic review. One subheading is always shown and all others are always hidden.

* Noun                                               :drill:
    :PROPERTIES:
    :DRILL_CARD_TYPE: multisided
    :END:

Translate.

** Spanish
la mesa

** English
the table

** Picture
[[file:table.jpg][PICTURE]]

The user will be shown the main text and either 'la mesa', or 'the table', or a picture of a table.

Multi-cloze cards

Often, you will wish to create cards out of sentences that express several facts, such as the following:

The capital city of New Zealand is Wellington, which is located in the
North Island and has a population of about 400,000.

There is more than one fact in this statement – you could create a single 'simple' card with all the facts marked as cloze text, like so:

The capital city of [New Zealand] is [Wellington], which is located in
the [North|North/South] Island and has a population of about [400,000].

But this card will be difficult to remember. If you get just one of the 4 hidden facts wrong, you will fail the card. A card like this is likely to become a leech.

A better way to express all these facts using 'simple' cards is to create several cards, with one fact per card. You might end up with something like this:

* Fact
The capital city of [New Zealand] is Wellington, which has a population of
about 400,000.

* Fact
The capital city of New Zealand is [Wellington], which has a population of
about 400,000.

* Fact
The capital city of New Zealand is Wellington, which has a population of
about [400,000].

* Fact
The capital city of [New Zealand] is Wellington, which is located in the
the North Island.

* Fact
The capital city of New Zealand is [Wellington], which is located in
the North Island.

* Fact
The capital city of New Zealand is Wellington, which is located in
the [North|North/South] Island.

However, this is really cumbersome. Multicloze card types exist for this situation. Multicloze cards behave like 'simple' cards, except that when there is more than one area marked as cloze text, some but not all of the areas can be hidden. There are several types of predefined multicloze card:

  1. hide1cloze – one of the marked areas is hidden during review; the others all remain visible. The hidden text area is chosen randomly at each review. (Note: this type used to be called 'multicloze', and that card type is retained as a synonym for 'hide1cloze'.)
  2. show1cloze – only one of the marked areas is visible during review; all the others are hidden. The hidden text area is chosen randomly at each review.
  3. hide2cloze – like hide1cloze, but 2 marked pieces of text will be hidden, and the rest will be visible.
  4. show2cloze – like show1cloze, but 2 marked pieces of text will be visible, the rest are hidden.

There are also some types of multicloze card where some pieces have an increased or decreased chance of being hidden. These are intended for use when studying languages: generally it is easy to translate a foreign-language sentence into your own language if you have met it before, but it is much harder to translate in the other direction. Therefore, you will want to test the harder direction more often.

  1. hide1_firstmore – only one of the marked pieces of text will be hidden. 75% of the time (guaranteed), the first piece is hidden; the rest of the time, one of the other pieces is randomly hidden.
  2. show1_firstless – only one of the marked pieces of text will be visible. Only 25% of the time (guaranteed) will the first piece will be visible; the rest of the time, one of the other pieces is randomly visible.
  3. show1_lastmore – only one of the marked pieces of text will be visible. 75% of the time (guaranteed), the last piece will be visible; the rest of the time, one of the other pieces is randomly visible.

So, for the above example, we can actually use the original 'bad' simple card, but change its card type to 'hide1cloze'. Each time the card is presented for review, one of 'New Zealand', 'Wellington', 'the South Island' or '400,000' will be hidden.

* Fact
  :PROPERTIES:
  :DRILL_CARD_TYPE: hide1cloze
  :END:

The capital city of [New Zealand] is [Wellington], which is located in
the [North|North/South] Island and has a population of about [400,000].

User-defined card types

Finally, you can write your own emacs lisp functions to define new kinds of topics. Any new topic type will need to be added to org-drill-card-type-alist, and cards using that topic type will need to have it as the value of their DRILL_CARD_TYPE property. For examples, see the functions at the end of org-drill.el – these include:

  • org-drill-present-verb-conjugation, which implements the 'conjugate' card type. This asks the user to conjugate a verb in a particular tense. It demonstrates how the appearance of an entry can be completely altered during a drill session, both during testing and during the display of the answer.
  • org-drill-present-translate-number, which uses a third-party emacs lisp library (spell-number.el) to prompt the user to translate random numbers to and from any language recognised by that library.
  • org-drill-present-spanish-verb, which defines the new topic type spanish_verb. This illustrates how a function can control which of an item's subheadings are visible during the drill session.

See the file spanish.org for a full set of example material, including examples of all the card types discussed above.

Empty cards

If the body of a drill item is completely empty (ignoring properties and child items), then the item will be skipped during drill sessions. The purpose of this behaviour is to allow you to paste in 'skeletons' of complex items, then fill in missing information later. For example, you may wish to include an empty drill item for each tense of a newly learned verb, then paste in the actual conjugation later as you learn each tense.

Note that if an item is empty, any child drill items will not be ignored, unless they are empty as well.

If you have an item with an empty body, but still want it to be included in a drill session, put a brief comment ('# …') in the item body.

Running the drill session

Start a drill session with M-x org-drill. By default, this includes all non-hidden topics in the current buffer. org-drill takes an optional argument, SCOPE, which allows it to take drill items from other sources. See below for details.

During a drill session, you will be presented with each item, then asked to rate your recall of it by pressing a key between 0 and 5. The meaning of these numbers is (taken from org-learn):

Quality SuperMemo label Fail? Meaning
0 NULL Yes Wrong, and the answer is unfamiliar when you see it.
1 BAD Yes Wrong answer.
2 FAIL Yes Almost, but not quite correct.
3 PASS No Correct answer, but with much effort.
4 GOOD No Correct answer, with a little thought.
5 BRIGHT No Correct answer, effortless.

You can press '?' at the prompt if you have trouble remembering what the numbers 0–5 signify.

At any time you can press 'q' to finish the drill early (your progress up to that point will be saved), 's' to skip the current item without viewing the answer, or 'e' to escape from the drill and jump to the current topic for editing (again, your progress up to that point will be saved).

After exiting the drill session with 'e' or 'q', you can resume where you left off, using the command org-drill-resume. This will return you to the item that you were viewing when you left the session. For example, if you are shown an item and realise that it is poorly formulated, or contains an error, you can press 'e' to leave the drill, then correct the item, then press M-x org-drill-resume and continue where you left off.

Note that 'drastic' edits, such as deleting or moving items, can sometimes cause Org-Drill to "lose its place" in the file, preventing it from successfully resuming the session. In that case you will need to start a new session.

Multiple sequential drill sessions

Org-Drill has to scan your entire item database each time you start a new drill session. This can be slow if you have a large item collection. If you have a large number of 'due' items and want to run a second drill session after finishing one session, you can use the command org-drill-again to run a new drill session that draws from the pool of remaining due items that were not tested during the previous session, without re-scanning the item collection.

Also note that if you run org-drill-resume and you have actually finished the drill session, you will be asked whether you want to start another drill session without re-scanning (as if you had run org-drill-again).

Cram mode

There are some situations, such as before an exam, where you will want to revise all of your cards regardless of when they are next due for review.

To do this, run a cram session with the org-drill-cram command (M-x org-drill-cram RET). This works the same as a normal drill session, except that all items are considered due for review unless you reviewed them within the last 12 hours (you can change the number of hours by customising the variable org-drill-cram-hours).

Leeches

From the Anki website, http://ichi2.net/anki/wiki/Leeches:

Leeches are cards that you keep on forgetting. Because they require so many reviews, they take up a lot more of your time than other cards.

Like Anki, Org-Drill defines leeches as cards that you have "failed" many times. The number of times an item must be failed before it is considered a leech is set by the variable org-drill-leech-failure-threshold (15 by default). When you fail to remember an item more than this many times, the item will be given the :leech: tag.

Leech items can be handled in one of three ways. You can choose how Org-Drill handles leeches by setting the variable org-drill-leech-method to one of the following values:

nil
Leech items are tagged with the leech tag, but otherwise treated the same as normal items.
skip
Leech items are not included in drill sessions.
warn
Leech items are still included in drill sessions, but a warning message is printed when each leech item is presented.

The best way to deal with a leech is either to delete it, or reformulate it so that it is easier to remember, for example by splitting it into more than one card.

See the SuperMemo website for more on leeches.

Customisation

Org-Drill has several settings which you change using M-x customize-group org-drill <RET>. Alternatively you can change these settings by adding elisp code to your configuration file (.emacs).

Visual appearance of items during drill sessions

If you want cloze-deleted text to show up in a special font within Org mode buffers, add this to your .emacs:

(setq org-drill-use-visible-cloze-face-p t)

Item headings may contain information that "gives away" the answer to the item, either in the heading text or in tags. If you want item headings to be made invisible while each item is being tested, add:

(setq org-drill-hide-item-headings-p t)

Duration of drill sessions

By default, a drill session will end when either 30 items have been successfully reviewed, or 20 minutes have passed. To change this behaviour, use the following settings.

(setq org-drill-maximum-items-per-session 40)
(setq org-drill-maximum-duration 30)   ; 30 minutes

If either of these variables is set to nil, then item count or elapsed time will not count as reasons to end the session. If both variables are nil, the session will not end until all outstanding items have been reviewed.

Saving buffers after drill sessions

By default, you will be prompted to save all unsaved buffers at the end of a drill session. If you don't like this behaviour, use the following setting:

(setq org-drill-save-buffers-after-drill-sessions-p nil)

Sources of items for drill sessions (scope)

By default, Org-Drill gathers drill items from the current buffer only, ignoring any non-visible items. There may be times when you want Org-Drill to gather drill items from other sources. You can do this by changing the value of the variable org-drill-scope. Possible values are:

file
The current buffer, ignoring hidden items. This is the default.
tree
The subtree starting with the entry at the cursor. (Alternatively you can use M-x org=drill-tree to run the drill session – this will behave the same as org-drill if 'tree' was used as the value of SCOPE.)
file-no-restriction
The current buffer, including both hidden and non-hidden items.
file-with-archives
The current buffer, and any archives associated with it.
agenda
All agenda files.
agenda-with-archives
All agenda files with any archive files associated with them.
directory
All files with the extension '.org' in the same directory as the current file. (The current file will also be included if its extension is .org)
(file1 file2 …)
A list of filenames. All files in the list will be scanned.

Definition of old and overdue items

Org-Drill prioritises overdue items in each drill session, presenting them before other items are seen. Overdue items are defined in terms of how far in the past the item is scheduled for review. The threshold is defined in terms of a proportion rather than an absolute number of days. If days overdue is greater than

last-interval * (factor - 1)

and is at least one day overdue, then the item is considered 'overdue'. The default factor is 1.2, meaning that the due date can overrun by 20% before the item is considered overdue.

To change the factor that determines when items become overdue, use something like the following in your .emacs. Note that the value should never be less than 1.0.

(setq org-drill-overdue-interval-factor 1.1)

After prioritising overdue items, Org-Drill next prioritises young items. These are items which were recently learned (or relearned in the case of a failure), and which therefore have short inter-repetition intervals. "Recent" is defined as an inter-repetition interval less than a fixed number of days, rather than a number of repetitions. This ensures that more difficult items are reviewed more often than easier items before they stop being 'young'.

The default definition of a young item is one with an inter-repetition interval of 10 days or less. To change this, use the following:

(setq org-drill-days-before-old 7)

Spaced repetition algorithm

Choice of algorithm

Org-Drill supports three different spaced repetition algorithms, all based on SuperMemo algorithms. These are:

SM2
an early algorithm, used in SuperMemo 2.0 (1988), which remains very popular – Anki and Mnemosyne, two of the most popular spaced repetition programs, use SM2. This algorithm stores an 'ease factor' for each item, which is modified each time you rate your recall of the item.
SM5 (default)
used in SuperMemo 5.0 (1989). This algorithm uses 'ease factors' but also uses a persistent, per-user 'matrix of optimal factors' which is also modified after each item repetition.
Simple8
an experimental algorithm based on the SM8 algorithm. SM8 is used in SuperMemo 8.0 (1998) and is almost identical to SM11 which is used in SuperMemo 2002. Like SM5, it uses a matrix of optimal factors. Simple8 differs from SM8 in that it does not adapt the matrix to the individual user, though it does adapt each item's 'ease factor'.

If you want Org-Drill to use the SM2 algorithm, put the following in your .emacs:

(setq org-drill-spaced-repetition-algorithm 'sm2)

Random variation of repetition intervals

The intervals generated by the SM2 and SM5 algorithms are pretty deterministic. If you tend to add items in large, infrequent batches, the lack of variation in interval scheduling can lead to the problem of "lumpiness" – one day a large batch of items are due for review, the next there is almost nothing, a few days later another big pile of items is due.

This problem can be ameliorated by adding some random "noise" to the interval scheduling algorithm. The author of SuperMemo actually recommends this approach for the SM5 algorithm, and Org-Drill's implementation uses his code.

To enable random "noise" for item intervals, set the variable org-drill-add-random-noise-to-intervals-p to true by putting the following in your .emacs:

(setq org-drill-add-random-noise-to-intervals-p t)

Adjustment for early or late review of items

Reviewing items earlier or later than their scheduled review date may affect how soon the next review date should be scheduled. Code to make this adjustment is also presented on the SuperMemo website. It can be enabled with:

(setq org-drill-adjust-intervals-for-early-and-late-repetitions-p t)

This will affect both early and late repetitions if the Simple8 algorithm is used. For the SM5 algorithm it will affect early repetitions only. It has no effect on the SM2 algorithm.

Adjusting item difficulty globally

The learn fraction is a global value which affects how quickly the intervals (times between each retest of an item) increase with successive repetitions, for all items. The default value is 0.5, and this is the value used in SuperMemo. For some collections of information, you may find that you are reviewing items too often (they are too easy and the workload is too high), or too seldom (you are failing them too often). In these situations, it is possible to alter the learn fraction from its default in order to increase or decrease the frequency of repetition of items over time. Increasing the value will make the time intervals grow faster, and lowering it will make them grow more slowly. The table below shows the growth in intervals (in days) with some different values of the learn fraction (F). The table assumes that the item is successfully recalled each time, with an average quality of just under 4.

Repetition F=0.3 F=0.4 F=0.5 F=0.6 F=0.7
1st 2 2 2 2 2
2nd 7 7 7 7 7
5th 26 34 46 63 85
10th 85 152 316 743 1942
15th 233 501 1426 5471 27868

To alter the learn fraction, put the following in your .emacs:

(setq org-drill-learn-fraction 0.45)   ; change the value as desired

Per-file customisation settings

Most of Org-Drill's customisation settings are safe as file-local variables. This means you can include a commented section like this at the end of your .org file to apply special settings when running a Drill session using that file:

# Local Variables:
# org-drill-maximum-items-per-session:    50
# org-drill-spaced-repetition-algorithm:  simple8
# End:

You can achieve the same effect by including the settings in the 'mode line' (this must be the first line in the file), like so:

# -*- org-drill-maximum-items-per-session: 50; org-drill-spaced-repetition-algorithm: simple8 -*-

In either case you will need to save, close and re-open the file for the changes to take effect.

Coping with large collections

If you keep all your items in a single file, it may eventually get very large. The file will be slow to load, and Emacs may have trouble syntax-highlighting the file contents correctly.

The easiest steps to solve this problem are:

  1. Move your file into its own dedicated directory.
  2. Divide the file into two or more smaller files.
  3. Within each file, set org-drill-scope to 'directory'. See per-file settings above for instructions about how to do this.

Sharing, merging and synchronising item collections

Every drill item is automatically given a persistent unique "ID" the first time it is seen by Org-Drill. This means that if two different people subsequently edit or reschedule that item, Org-Drill can still tell that it is the same item. This in turn means that collections of items can be shared and edited in a collaborative manner.

There are two commands that are useful in this regard:

  1. org-drill-strip-all-data - this command deletes all user-specific scheduling data from every item in the current collection. (It takes the same optional 'scope' argument as org-drill to define which items will be processed by the command). User-specific data includes scheduling dates, ease factors, number of failures and repetitions, and so on. All items are reset to 'new' status. This command is useful if you want to share your item collection with someone else.
  2. org-drill-merge-buffers - When called from buffer A, it prompts you for another buffer (B), which must also be loaded into Emacs. This command imports all the user-specific scheduling data from buffer B into buffer A, and deletes any such information in A. Matching items are identified by their ID. Any items in B that do not exist in A are copied to A, in the same hierarchical location if all the parent headings exist, otherwise at the end of the buffer.

An example scenario:

Tim decides to learn Swedish using an item collection (.org file) made publically available by Jane. (Before publishing it Jane used 'org-drill-strip-all-data' to remove her personal scheduling data from the collection.) A few weeks later, Jane updates her collection, adding new items and revising some old ones. Tim downloads the new collection and imports his progress from his copy of the old collection, using 'org-drill-merge-buffers', using the new collection as buffer A and the old one as buffer B. He can then discard the old copy. Any items HE added to HIS copy of the old collection (buffer B) will not be lost – they will be appended to his copy of the new collection.

Of course the sharing does not need to be 'public'. You and a friend might be learning a language or some other topic together. You each maintain a card collection. Periodically your friend sends you a copy of their collection – you run org-drill-merge-buffers on it, always using your own collection as buffer B so that your own scheduling progress is carried over. Other times you send your friend a copy of your collection, and he or she follows the same procedure.

Incremental reading

An innovative feature of the program SuperMemo is so-called "incremental reading". This refers to the ability to quickly and easily make drill items from selected portions of text as you read an article (a web page for example). See the SuperMemo website for more on incremental reading.

Much of the infrastructure for incremental reading is already provided by Org Mode, with the help of some other emacs packages. You can provide yourself with an incremental reading facility by using 'org-capture' alongside a package that allows you to browse web pages either in emacs (w3 or emacs-w3m) or in the external browser of your choice (org-protocol).

Another important component of incremental reading is the ability to save your exact place in a document, so you can read it incrementally rather than all at once. There is a large variety of bookmarking packages for emacs which provide advanced bookmarking functionality: see the Emacs Wiki for details. Bookmarking exact webpage locations in an external browser seems to be a bit more difficult. For Firefox, the Wired Marker addon works well.

An example of using Org-Drill for incremental reading is given below. First, and most importantly, we need to define a couple of org-capture templates for captured facts.

(setq org-capture-templates
       `(("u"
         "Task: Read this URL"
         entry
         (file+headline "tasks.org" "Articles To Read")
         ,(concat "* TODO Read article: '%:description'\nURL: %c\n\n")
         :empty-lines 1
         :immediate-finish t)

        ("w"
         "Capture web snippet"
         entry
         (file+headline "my-facts.org" "Inbox")
         ,(concat "* Fact: '%:description'        :"
                  (format "%s" org-drill-question-tag)
                  ":\n:PROPERTIES:\n:DATE_ADDED: %u\n:SOURCE_URL: %c\n:END:\n\n%i\n%?\n")
         :empty-lines 1
         :immediate-finish t)
        ;; ...other capture templates...
    ))

Using these templates and org-protocol, you can set up buttons in your web browser to:

  • Create a task telling you to read the URL of the currently viewed webpage
  • Turn a region of selected text on a webpage, into a new fact which is saved to whichever file and heading you nominate in the template. The fact will contain a timestamp, and a hyperlink back to the webpage where you created it.

For example, suppose you are reading the Wikipedia entry on tuberculosis here.

You read the following:

The classic symptoms of tuberculosis are a chronic cough with blood-tinged sputum, fever, night sweats, and weight loss. Infection of other organs causes a wide range of symptoms. Treatment is difficult and requires long courses of multiple antibiotics. Antibiotic resistance is a growing problem in (extensively) multi-drug-resistant tuberculosis. Prevention relies on screening programs and vaccination, usually with Bacillus Calmette-Guérin vaccine.

You decide you want to remember that "Bacillus Calmette-Guérin vaccine" is the name of the vaccine against tuberculosis. First, you select the `interesting' portion of the text with the mouse:

The classic symptoms of tuberculosis are a chronic cough with blood-tinged sputum, fever, night sweats, and weight loss. Infection of other organs causes a wide range of symptoms. Treatment is difficult and requires long courses of multiple antibiotics. Antibiotic resistance is a growing problem in (extensively) multi-drug-resistant tuberculosis. Prevention relies on screening programs and vaccination, usually with Bacillus Calmette-Guérin vaccine.

Then you press the button you created when setting up org-protocol, which is configured to activate the capture template "w: Capture web snippet". The selected text will be sent to Emacs, turned into a new fact using the template, and filed away for your later attention.

(Note that it might be more efficient to turn the entire paragraph into a drill item – since it contains several important facts – then split it up into multiple items when you edit it later in Emacs.)

Once you have had enough of reading the article, save your place, then go to your "fact" file in Emacs. You should see that each piece of text you selected has been turned into a drill item. Continuing the above example, you would see something like:

** Fact: 'Tuberculosis - Wikipedia, the Free Encyclopedia'        :drill:

Prevention relies on screening programs and vaccination, usually with Bacillus
Calmette-Guérin vaccine.

You need to edit this fact so it makes sense independent of its context, as that is how it will be presented to you in future. The easiest way to turn the text into a 'question' is by cloze deletion. All you need to do is surround the 'hidden' parts of the text with square brackets.

Prevention of tuberculosis relies on screening programs and vaccination,
usually with [Bacillus Calmette-Guérin vaccine].

You can of course define browser buttons that use several different "fact" templates, each of which might send its fact to a different file or subheading, or give it different tags or properties, for example.

Author

Org-Drill is written by Paul Sexton.

Documentation from the http://orgmode.org/worg/ website (either in its HTML format or in its Org format) is licensed under the GNU Free Documentation License version 1.3 or later. The code examples and css stylesheets are licensed under the GNU General Public License v3 or later.