Concepts in SuperMemo can be used to organize knowledge. They can be used to add elements to dedicated subject branches of the knowledge tree (e.g. chemistry branch, biology branch, etc.). They can also be used to inter-link elements stored in various branches into networks called concept maps (e.g. flu virus knowledge). Concepts also underlie a powerful problem solving tool based on a new type of subset review: neural review (see: Neural creativity for more).

Concepts terminology

A concept is an element associated with an idea or subject. Multiple elements can form links to a concept. Links indicate that elements are associated with the idea represented by the concept. For example, if you learn about infections, you can define a concept flu virus. You can link this concept with many elements related to flu. Each time you want to learn about flu, you might begin from the concept flu virus.

This article focuses on concept groups. A concept group is a branch in the Contents window associated with a concept such as chemistry, biology, geography, my family, pictures, etc. The term concept is used in four main contexts:

concept element
element used to build a portion of a concept map (e.g. an idea, or an article from Wikipedia, etc.)
concept member
member of the concept registry used in concept housekeeping (esp. concept search uses when building a concept map)
concept group
branch of elements rooted in a concept. This is similar to category known from older SuperMemos. For performance reasons, elements in the concept group are not registered with a concept. Even though concept groups are used in spreading activation in neural creativity the links formed by parent-child-sibling relationships are taken as only carrying minor priority (in comparison to concept-concept, concept-element and element-element links set by the user)
concept map
interlinked graph of elements used as the skeleton for spreading activation. It may also be used in reference to its diagrammatic representation

Concept groups

When you work with a collection which includes material belonging to different subjects, you may want to keep different subjects in different sections of the knowledge tree available in the Contents window (e.g. economics, computer science, geography, etc.).

To help you organize different subjects in one collection, SuperMemo employs concept groups. A concept group is set of elements added to a knowledge tree branch associated with a given concept. A concept group can be seen as a tool for building a section of the knowledge tree. One concept group is used for adding material related to one subject. Elements added to a given concept group may use their own template that determines their look (e.g. images, sounds, colors, fonts, sizes of text fields, number of shape components, etc.). For more about templates, see: Using templates.

In older SuperMemos, the role similar to concept groups was played by categories. The main difference between concept groups and categories is that the former are associated with concepts that play multiple roles in SuperMemo (starting with SuperMemo 17).

The optimum strategy for maximizing the inflow of quality knowledge into the learning process at minimum time is to create a To Do concept group, to which you add all the knowledge you want to master (e.g. articles, rough notes, rough items, etc. belonging to all various subjects). You can process this To Do knowledge for optimal recall in the course of repetitions. Only when items assume their ultimate well-structured shape (see: 20 rules of formulating knowledge), move them to their target concept group.

Creating concept groups

Suppose you would like to create a dedicated concept group for your items related to the European Union simply called European Union. Instead of the Item template, which is the default template used for all newly added items, you could define your custom European Union template to be used with this concept group. All items added to the concept group will share the European Union look (i.e. have the European Union template applied). You will only need to select European Union in the Default concept group box in the navigation bar at the top of the element window.

You can easily create a new concept group using the following steps:

  1. Choose Edit : Create a concept on the main menu
  2. Type in the name of a new concept group (e.g. geography, biology, etc.), and
  3. Click OK to confirm its creation

Choose short names for your concept groups so they would be easily identifiable in the Default concept group box on the in the navigation bar.

This will add a new concept element as a child of the root of the collection. Alternatively, you can convert any existing topic/task element into a concept by using Commander's Concept: Make on that element.

If you want the elements related to a selected concept group have custom looks, you can change its templates via Search : Concepts (from the main menu) at any time. Item template will determine the look of your question-answer items in the concept group. You can also choose other template formats for items (e.g. occlusion test, multiple choice test, etc.). Topic template will define how the articles added to the concept group will look like (e.g. when you import them with Ctrl+N in incremental reading).

Creating concept groups: Tips

Using concept groups

When you click the Add new button, a new element is created in the location and using the template determined by the current concept group (as chosen in the Default concept group box in the navigation bar at the top of the element window).While you are adding new elements, if you decide you want this element to go into a different major portion of the knowledge tree then all you have to do is change the current concept group before creating the new element. That new element will then be appended in the appropriate location of that other section of the tree and the appropriate template will be used. If you start creating elements for a different subject then you just change the default concept group again.In order to achieve this convenience it may be necessary to create a rather large set of concept groups, especially if you keep all your information in one collection. You may want to create concept groups for more than just each major "group" of information. You may want to create one for each type of question you might ask for each different subject. You may even want to break your subjects down into smaller sub-topics so that you can choose an appropriate concept group to get the new elements closer to other related information.

In incremental reading, instead of frequently changing concept groups while adding new elements, you are more likely to use a big TO DO concept group, and move individual items to their final concept groups only when they are finished in the incremental learning process (e.g. via the Element parameters dialog box available by choosing Edit : Element parameters from the element menu, or pressing Shift+Ctrl+P).

Moving elements to a concept group

Moving a single element

Suppose you had imported an article about Irish referendum on the expansion of the European Union. Imagine that in the course of incremental reading you extracted an item that you have polished over the last several repetitions and now would like to move to your European Union concept group.

To move an element to a selected concept group:

  1. Right-click over the navigation bar (e.g. navigation buttons), and choose Edit : Element parameters (Ctrl+Shift+P) from the element menu,
  2. In the Element parameters dialog box, select the target concept group from the Group drop-down menu (e.g. European Union),
  3. Click OK to close the dialog box and save the selection you have made
Moving a subset of elements

Use browser to move a subset of elements to a desired concept group:

  1. On the browser toolbar, click the Subset processing menu button (2nd from the left), and then choose Move : To a concept,
  2. In the Concept registry, in its left pane, select the concept that you want to move a given subset of elements under,
  3. Click the Accept button to close the registry window and move the subset of elements listed in the browser to the concept group related to the selected concept,
  4. Click Yes to the Do you want to move all browser elements? query,
  5. Click OK on an information dialog reporting how many elements have been successfully moved to under the selected concept

Tips on working with concepts groups

Concept registry

The concept registry is used to keep the sorted list of concepts. Each concept is associated with a concept registry member.

In the registry, each concept also shows a set of properties that can be used in managing a concept group.

The concept registry can be opened with Search : Concepts on the main menu. You may find it useful in the following circumstances:

It is not recommended to change Root element or Hook branch manually (unless you fully understand the way SuperMemo builds concept folders under the concept root). Choosing it wrongly may result in an unexpected rearrangement of your entire knowledge tree (SuperMemo rebuilds the concept group branch when you add too many elements to its hook node).

Concept properties

If you would like to change concept properties, choose Search : Concepts on the main menu, or click the button to the left of the Default concept group box in the navigation bar. It will open the concepts registry with all concepts that you have defined for the collection:

SuperMemo: Concept registry which you can use to execute neural review on selected members and change their properties

Each concept in the registry is characterized by the following properties (compare with the picture above):

Neural review

Neural review is a type of review that follows meaningful connections between pieces of knowledge. It takes inspiration from how the brain follows associated ideas. Neural review automates the review of knowledge associated with selected concepts or ideas, e.g. in problem solving, creative writing, etc.For example, in a neural review of dogs, there is a good chance of learning about puppies or puddles, but there is also a chance of learning about cats and somewhat lesser chance of learning about cars. Neural review follows the spread of neural activation in a network of inter-element connections. Elements are linked with concepts, other elements, or form connections with their neighbors in the knowledge tree. All those links and connections receive weights based on their importance and the priority of connected elements. Neural review follows those connections and is initiated by executing Learn : Go neural (Ctrl+F2). Neural review carries a degree of randomness. As such it can be very helpful in associating ideas in neural creativity. See also: Spreading activation

Neural creativity

Neural creativity is creativity induced with the help of neural review. In neural review, SuperMemo successively feeds the user with knowledge associated with a selected topic or a chosen subset of topics. When a network of conceptual links connects areas of knowledge, they form semantic space that can be explored in a neural manner that helps forming new associations, and generate ideas. This process is conducive to research, invention, problem solving, etc. Metaphorically speaking, neural creativity helps emulate a thinking process in a human brain extended by knowledge stored in SuperMemo.

Neural creativity employs the incremental learning process to produce new ideas in a neural fashion. In neural creativity, closely related concepts are more likely to show up when executing a neural review of a studied subject. If you are fluent in incremental learning, you may wonder how a neural review differs from a semantic review. The main difference is that in semantic review the whole burden of juggling the semantics is in your hands. You need to know the tools of incremental learning to execute a semantic review well. In neural review, the whole process will be reduced to pressing a single button in SuperMemo.

Unlike it is the case with semantic review in SuperMemo, or simply googling for knowledge, the whole process of associating pieces of knowledge is automated. To give it a try, pick a subject and Go neural (Ctrl+F2).

For more see: Neural creativity.


Concept groups make it easy to add same-looking elements to a selected branch of the knowledge tree (in the Contents window). You can just keep pressing the Add new button confident that the new element is going to end up right at the end of the list of elements under the hook node of the concept group you are currently working with. If you decide to look at some other element in the knowledge tree, you can go right back to adding new elements and they will still be added where they were being added before. This way, if you are reviewing elements in the tree and decide to add another element, it will go at the end of the list of elements for that concept group where it belongs.


Here is the typical way of working with concept groups:

  1. Use Concept: Make in the Commander to convert a branch to a concept
  2. Use Template : Save as default on the element menu to save the default element template (or use Search : Concepts to change concept templates)
  3. To start adding elements to another concept group (e.g. to start working with Chemistry after finishing your work with Geography), choose the new working concept group in the Default concept group box in the navigation bar at the top of the element window
  4. To move a ready item from under the TO DO concept to a target concept group (e.g. Chemistry):
    1. press Shift+Ctrl+P to open the Element parameters,
    2. select the target concept group in the Group drop-down menu, and
    3. choose OK to confirm your selection and close the dialog box


Where is Search : Concepts?

(Serguei Koureda, Sunday, October 20, 2002 11:08 PM)


Why is there no option Concepts in Search menu?


You need to switch to the Professional level (File : Level) If you use less advanced levels, some menu options may be turned off.

Add new adds to a collection not a specific concept group

(Barrett L. Oct 01, 2007, 09:09:33)


When I am working in a concept group and want to add a new item, I click Add new. However, this creates a child in my collection, and does not place the new item in the appropriate folder. How do I add new items directly to a concept group?


Where Add new appends new items depends on the currently selected concept group. If you create a new collection, it has one element (the root element) which also makes up the only and current concept group in the collection. If you want Add new to append items to a given concept group (provided there are more concept groups in your collection), you need to select it first in the Default concept group combo box in the navigation bar at the top of the element window.

Importing data into a specific concept group

(Barrett L., Oct 01, 2007, 09:09:33)


I am having some difficulty importing data. For some reason, I cannot import data into a specific concept group. I have the concept group that I wish to import data selected/opened, but when I "import" all the data simply goes directly into my collection. I can then manually drop this imported data into the appropriate concept group, but this is cumbersome.


If you want to import data into a specific concept group, it is not enough if you just select it in the Contents window. You need to select it to be the current concept group for your collection. You do it by using the Default concept group box in the navigation bar at the top of the element window.

Use Add in the Contents window to place an item in the knowledge tree

(R.K., Sun, Jun 17, 2001 17:54)


I would expect SuperMemo to add a new item as a straight neighbor of the previously added element in the Contents window. Why isn't it so?


Selection in the Contents window is too transient to be the basis of choosing the insertion point for new material with Add new (Alt+A). This would require constant user attention as to the present selection. As a remedy, the notion of a concept group has been introduced. Each concept, such as biology or geography, has its own insertion point called a hook. Now, all you have to do is to select a concept group in the Default concept group box in the navigation bar, and Add new will add new items under that concept. Added elements will be listed sequentially as neighbors. However, if you would like to add new items to the location determined by the selection in the Contents window, use Add at the bottom of the window instead.

Branch selection does not affect the template used

(Vidar Garlie, Norway, Mar 18, 1999)


When I go to the Contents window, select a concept branch and press Alt+A, the template of this concept group is not used! Can you help?


To use a concept template, you have to first choose the concept group in the Default concept group box in the navigation bar. Selecting branches in the Contents window does not affect the current concept group selection.

Searching a concept group

(Maarten Mols, Mon Feb 17, 2003 4:23 am)


How can I limit Search : Find elements to a certain concept group?


  1. Go to the root of the concept group (in the Contents window)
  2. Choose Search branch (Ctrl+F)


  1. Search for the term
  2. In the search browser, choose Child : Branch (and select concept group root)


  1. Open the concept group in the browser (View : Branch in the Contents window on the concept group root)
  2. Choose Search browser (Ctrl+F)

You can make repetitions on elements belonging to a given branch

(louis_lheureux, Canada, Monday, November 18, 2002 11:22 PM)


Is there a way to make a given concept group the default concept group for learning each time I press the Learn button?


No. However, you can select a given branch in the Contents window and make repetitions only on elements that belong to this branch. To make repetitions only in a given branch:

  1. Press the Contents button (Alt+C) to switch to the Contents window,
  2. In the Contents window, select a branch, in which you would like to make repetitions,
  3. Press the Learn button (Ctrl+L) to start repetitions on elements that belong to the selected branch

You can rehearse only those elements that belong to a selected concept group

(louis_lheureux, Canada, Monday, November 18, 2002 11:22 PM)


In my daily random repetitions of the outstanding material, I have stumbled upon an element that belongs to my History concept group. Is there a quick way to make repetitions on the rest of elements belonging to this concept group?


Once you see any element that belongs to a given concept group, right-click your mouse and then choose Learning : Learn branch from the element menu

Reviewing concept group elements ahead of their schedule

(Sat Feb 6, 2010 10:26 pm)


If I review all elements in a concept group, will SuperMemo adjust the reviewing process to fit what I need to review after that?


Yes, however, you need to use the one of the Review options as opposed to one of the Test options. For example:

  1. Click Contents in the element window, and, in the Contents window, select the concept group branch/folder you want to review the elements of, and press Ctrl+Space to display them in the browser
  2. Then press Ctrl+L to review the outstanding elements from the browser

Are concept groups treated distinctively in learning?

(anonymous, Jul 22, 2010, 16:10:40)


I was wondering if concept groups are treated differently concerning the scheduling of the items, since different subjects hold different levels of difficulty.


Items belonging to different concept groups are treated in the same way. The only difference is that you can define a default priority for the entire concept group. New items added to a modified concept group will have a distinctive priority. This way they can be reviewed more often, or less often, and they can be remembered better, or worse, depending on the setting and how overloaded your learning process is.

You can make SuperMemo automatically apply concept group template when moving an element to a concept group

(Anatoliy Lipatov, Ukraine, Friday, January 10, 2003 8:59 AM)


Each time I create an extract, SuperMemo asks me the following question:

Do you want to apply this template? Article

Is there an option to turn it off?


  1. Open the concept registry with Search : Concepts from the main menu,
  2. In the left pane, click the concept group, which you would not like SuperMemo not to ask this question for,
  3. In the top-right pane, click the Auto-apply topic templates checkbox until it is checked and not grayed

Applying concept group template without being prompted about it

(Kyle F., Sunday, August 24, 2008 11:33 PM)


When I create a cloze deletion, Supermemo asks me Do you want to apply this template?. I ALWAYS want to apply the concept group template. Can get SuperMemo to apply the concept group template without asking me?


Yes, you can. You need to go to the concept registry. You can do that by selecting Search : Concepts from the main menu. In the top right pane, there is a group of Auto-apply... checkboxes. Each checkbox has the following three states:

You need to click a relevant Auto-apply... checkbox to change the control state from the grayed checked to checked state. This will solve your problem.

Remember, since it is a concept group-specific setting you need to do it for each and every concept in the registry.

How can I change the layout for each concept group?


How could I configure a single element in a concept group with a different layout than the others in the same concept group?

Whenever I adjust the layout (i. e. increase/decrease the size of a text box), the layout changes for all the elements in the concept group. is there a way to prevent that from happening?


Use Template : Detach template on the element menu before you start making any changes to a given element.

Note that the term layout is used to describe the position and size of windows in SuperMemo. For the position and size of components, we use the term template.

Each concept group has its own hook

(Ahmet, Tuesday, December 10, 2002 9:07 PM)


Could you please introduce a shortcut key for the Set hook command available in the Contents window as I add a lot of new elements and have to use it each time a given element is from different discipline?


You do not need to set a hook for a given concept group each time you would like to add new elements to it. When you create concept groups, each has by default its own hook, which is usually the root node of a given concept group. If you would like to add elements to a different concept group, you change the active concept group to the one, to which you would like to add new elements. You can change the active concept group by selecting it in the Default concept group box in the navigation bar.

What's the use of the concept group's root node

(Alessandro, Monday, April 19, 2010 5:32 AM)


I can understand the use of the hook node. But the root node has no apparent use.


Being able to locate the root node of a given concept group is helpful when you want to execute operations (e.g. apply specific template) on the child elements of this concept group. When you know it, it is enough you right-click it in the Contents window and choose Process branch> from the pop-up menu. This will display another pop-up menu with a number of operations you will be able to perform on the elements belonging to this node.


The most important function of the root node is technical. This function is fulfilled without your involvement. If you exceed the number of children in a node, a new node is created. However, if you exceed the number of nodes, the entire concept group tree needs to be rearranged. Those changes will happen under the root node. Other portions of the tree will not be affected to make sure the rearrangement does not touch elements that belong to other concept groups. If you have thousands of elements under the root, you may need a few levels of nodes to make sure no node exceed the children limit per branch. Those extra levels are added only when needed. If your children limit is 50, you will need one level until you reach 50 elements, then the level #2 is added providing spaces for roughly 50x50=2500 elements. If you run out of that space, Level #3 will provide for 50x50x50=125,000 elements (minus folder elements). You are then unlikely to run out of space for Level #4 that will hold over 6 million elements.

Applying filter to a selected concept group

(Manuel S., Thu Oct 15, 2009 2:22 pm)


Is it possible to apply the filter to a selected concept group only?



  1. Right-click the concept group root in the Contents window, and press Ctrl+Enter
  2. In the browser, right-click, choose Subset : Save all to save the concept group's elements to a subset file, and close the browser
  3. From the main menu, choose View : Filter to apply a selected set of criteria to the entire collection
  4. In the browser (that opens with the collection's elements that satisfy the chosen criteria), right-click, choose Subset : Intersect subset file, and select the subset file saved in Step #2