Litmaps can lay out your articles in four ways. The default Citation map places articles by publication date and citation count. Three newer views place related articles near each other instead, and shade and name each group for you:
Semantic map: articles with similar titles and abstracts are placed together.
Co-citation network: articles that are cited together, or that cite the same papers, are placed together, even when they don't cite each other.
Co-author network: articles that share authors are placed together, so each research group's work gathers in one place.
⭐ The Semantic map, the Co-author network and the shaded groups on every view are part of Litmaps Pro. The Co-citation network is free for everyone.
Which view should I use?
View | Articles are placed together when they… | Use it to… |
Citation map | are published around the same time and have similar citation counts | see how a field developed and which articles had the most impact |
Semantic map | are about similar things | see the topics a field is made of, and where your reading is thin |
Co-citation network | are cited by the same papers or cite the same papers | find the schools of thought that researchers treat as related |
Co-author network | share authors | see the research groups behind a field and who works with whom |
How to change your Litmap's view
Open a Litmap
Click one of the axis labels to open Layout Settings
Under Map view, choose Semantic map, Co-citation network or Co-author network
Choose whether to Keep the timeline:
On: publication dates stay across the Litmap, and related articles are grouped up and down. This shows how each group has developed over time.
Off: both axes are used to place related articles together, giving a full 2D map. This gives the clearest view of the groups.
To go back to the default layout, choose Citation map.
In these views, only the distance between articles matters. Articles that are close together are related. The direction (up, down, left or right) doesn't have a meaning of its own.
Semantic map
Litmaps uses AI to read each article's title and abstract and work out how similar it is to the other articles on your Litmap. Articles about similar things are placed close together, and each group of similar articles (a semantic cluster) is shaded and given a short theme label.
Citation lines are still drawn between articles, so you can see both what articles are about and how they cite each other.
The Semantic map is in beta. If anything looks wrong or you'd like guidance, contact us through the chat bubble.
Group articles by your own topics
On a Semantic map, Litmaps finds the clusters for you. You can name the topics yourself instead, such as the chapters of your thesis or the themes of your review. Each article is then grouped under the topic it's most similar to.
In Layout Settings, go to Advanced Settings
Under Cluster Topics (Beta), type a topic and press Enter (or click +)
Add as many topics as you need, up to 50
Changing your topics changes how articles are grouped and labelled, but doesn't move them. Every article goes under the closest topic in your list, even if it isn't a strong match. To go back to the clusters Litmaps finds, remove all of your topics.
Co-citation network
The Co-citation network places articles together when the rest of the literature treats them as related, even if they never cite each other. It's similar to the approach used by Connected Papers.
You can choose how articles are related. In Layout Settings, go to Advanced Settings, then use Related by under Lines:
Cited together: how many papers cite both articles.
Shared references: how many references the two articles have in common.
Both (default): combines the two.
These counts cover all of Litmaps' database, not just the articles on your Litmap. Lines connect related articles, and thicker lines are more strongly related. Each community of closely related articles is shaded and given a short theme label.
Co-author network
The Co-author network places articles together when they share authors, so each research group's work gathers in one place. Lines connect articles by the same people, and thicker lines share more of their authors.
Each group of articles is shaded and named after the authors who appear on most of its articles.
The Co-author network starts as a full 2D map, because grouping authors along a single axis squeezes the groups together. You can still turn on Keep the timeline if you'd like dates across the Litmap.
Reading groups
In each of the three views, related articles are grouped together:
Shading: a coloured background outlines the articles in each group.
Labels: each group is given a short name. Semantic clusters and co-citation communities are named by AI from the titles of their articles. Co-author groups are named after their main authors. A simple keyword label may show for a moment while a name loads.
Group names are suggestions, so check them against the articles.
How to save a group as a tag
You can turn any group into a tag so you can come back to its articles later.
Click a group's name on the map to select all of its articles
To select more than one group, hold Shift (or Cmd on a Mac) and click another group's name. Do the same to remove a group from your selection.
Click Save as Tag in the selection bar
The tag is named after the group. If you already have a tag with that name, you'll see Add to <tag name> instead.
How to change groups and lines yourself
Each view sets three things at once: where articles are placed (the axes), which groups are shaded, and what the lines show. You can change each of these on its own in Layout Settings > Advanced Settings:
Lines connect articles that: Cite each other, Are related (co-citation) or Share authors.
Highlight groups by: Automatic (follows the view), Nothing, Semantic clusters, Co-citation communities or Same authors.
Cluster Shading (Beta) and Cluster Labels (Beta): show or hide the shading and the group names.
For example, you could keep the usual Citation map but shade its co-citation communities. When you mix settings like this, the Map view shows Custom. Choose a view again to reset all three.
You can also choose Content Similarity (Beta), Co-citation Network or Co-author Network for a single axis in the Horizontal Axis or Vertical Axis tab.
Using map views while exploring
When you're exploring related articles, you can see where the recommendations fit among the groups on your Litmap. Open the results layout menu and, under Change the map view, choose Semantic map (Beta), Co-citation network or Co-author network.
Tips
Map out a new field: use the Semantic map with Keep the timeline off to see the main topics before you start reading.
Find gaps in your review: add your planned sections as Cluster Topics on a Semantic map. A topic with few articles may need more reading.
Find related work that doesn't cite each other: use the Co-citation network. Articles in the same community are treated as related by other researchers.
Find the groups to follow: use the Co-author network to see which labs drive a field, then save a group as a tag.
Compare views: an article that sits in one semantic cluster but a different co-citation community may connect two areas.
Limitations and FAQ
Semantic map: placement is based on titles and abstracts, so articles with a short title and no abstract may not be placed as accurately.
Co-citation network: very new articles have few citations, so they may have few or no co-citation links. Try Shared references to relate them by their reference lists instead.
Co-author network: authors are matched using our author records where we have them, and by name otherwise. Different people with the same name may occasionally be treated as one person.
Group names are made automatically and may not always match how you'd describe the field.
If your Pro subscription ends: Litmaps set to the Co-author network show as a Co-citation network, and groups aren't shaded. Your settings are kept, so everything comes back if you upgrade again.
Questions or feedback? Let us know through the chat bubble.