The screen is composed of two frames: the map area in the center of the screen and the settings area on the left-hand side.
The map area
The map area contains the online political debate map, presented with its nodes and edges.
The nodes represent websites. The edges represent hyperlinks between websites.
The size of a node as well as the quantity of edges displayed depend on different parameters found in the settings area (see below). The pale blue zones in the map indicate a high density of links.
Navigating the map with your mouse
Use your mouse scrolling button to zoom in and out.
Hold down the left button to move to different areas of the map.
The settings area
A navigation panel in the top left hand corner of your screen shows the specific location you are currently viewing inside the map.
The slider is used to zoom in or out.
This navigation panel allows you to display the map in two different ways: Classic View (default view) and the Fish Eye View (wide angle view close to 180°).
Size of the nodes
The size of a node is either determined by its Linkfluence Degree (Lf).
The size of a node is proportional to the number of inbound links. The more inbound links there are, the bigger the node is.
Categories and Colors
Each category has been assigned a specific color, displayed close to its name.
The “Hide All” and “Show All” buttons allow to display or hide all the nodes on the map. Clicking on a category will display or hide all this category’s nodes.
The distribution of the different categories on the map can be seen as a pie chart or a bar chart. They help you to see the part of each category, due to the number of their elements.
Roll over the various segments of the charts to have more details on each category (number of nodes, percentage of the total number of nodes on the map).
When a website is selected, all the links to and from it are shown.
Additional information on the selected website (thumbnail picture, category, number of links, site family) is available in the settings area.
It is possible to search for a specific site on the map, based on its name in full or in part.
You can restrict the search to a specific category.
The results will be displayed at the bottom of the search panel.
By default, all the edges on the map are displayed.
In darkblue are displayed simple links (from a site A to a site B) and in lightblue mutual links (when sites A and B link back and forth to each other).
3 different colors show the nature of the links for selected websites: inbound links to a website are red, outbound links from a website are yellow, and mutual links between two websites are green.
If your computer is powerful, you may choose the antialiased render.
The maximal links size slider enables the displaying of links based on their lengths between two sites.
Curious about the Politicosphere map? Here are some answers to the most common questions asked:
I. Drawing the map
The Politicosphere map is composed of the 612 most visible and influential websites and blogs using Linkfluence™’s proprietary crawl technology.
The map includes both social media and mainstream media outlets. The sites are divided into 3 different categories, or communities (manually labelled):
In terms of methodology, we initiated the process by focusing on a set of a few hundred websites and blogs well-recognized by search engines and other sites related to U.S. politics. Then, we collected the URLs of all sites located just one click away from our initial set – which amounted to tens of thousands of websites.
Why was this step important? Because when it comes to networks – and the web is one giant network – there’s a rule that says that what’s similar to a given node in terms of content will stand close to this node in terms of location. Working with a set of websites large enough, one can collect all the other important websites dealing with the same topics using the “one click removed” idea.
Thanks to a series of metrics, both topology-related (i.e. how many sites link to a particular site) and semantics-related (i.e. are the words used of political nature), we were able to single out over 4,000 websites that constitute the core of the U.S. political webosphere. From these, we extracted the most link-relevant 612 sites.
II. Navigating the map
The politicosphere map’s default view is set to display all the categories at once. You can select the individual communities you’re interested in and more carefully analyze the links existing between them – most notable to see who links to whom, and what their level of authority is within their community.See the notice for more practical details on map navigation.
III. Understanding the map
As shown in the map’s navigation bar, a node’s color indicates the community it belongs to, and a node’s size indicates its linkfluence degree.
The more links a node receives from other nodes shown on the map, the bigger it appears on the map. Note that the link count is based solely upon links coming from nodes on the map. Links coming from websites located outside of the map are excluded. Based on this approach, we can determine the level of authority attributed to a given site within these communities. This approach may occasionally favor bloggers who splog (spam-blog) others, artificially generating inbound links to their blogs by an abusive use of such techniques as trackbacks. Given the size of the map’s set of websites, we were able to make sure such artificial results were not present.
Nodes are positioned on the map according to a topological placement algorithm, i.e. each node is positioned solely according to its linking pattern, without consideration for the stated political affiliation of the site or its content.
Many algorithms make possible for a 2D rendering of an adjacent matrix – i.e. the matrix describing any graph. We used a Fruchterman Rheingold algorithm, which shares with all the others the same basic principle: minimizing the system’s energy while maximizing the use of the space available for the representation of the data. To minimize the system’s energy, one can for instance assume that nodes that are not linked to each other are pushing away from each other whereas nodes that are linked to each other are attracting each other. Through iterative steps the algorithm tries to find a way to position nodes where there is as little link overlap as possible. To maximize the use of the mapped space, the graph is spread as much as possible over the surface allocated for its display.
These positioning principles call for the following reading conventions:
- A site’s position on the map depends solely upon its linking policy. A node has no predefined position, the latter being the result of the relations it has with other nodes. This means that a node with no links at all cannot be positioned on the map, which is why we excluded such websites from the Politicosphere map;
- North, East, South and West don’t matter. The displayed space is not based on the cardinal system (North, East, South, West), which means that the choice of a relative left-right or top-down position is purely arbitrary.
- Hubs are center-stage. The displayed space is polarized in a center to periphery tension. The nodes positioned at the center are the ones receiving the most links from other nodes that don’t link much to one another (exogamous nodes). The nodes positioned at the periphery receive fewer links but they receive them from other nodes that tend to link to one another (endogamous nodes). For instance, the politicosphere map clearly shows the pivotal position held by the infopros, the sites which set the agenda, which are conversation starter, receiving links from sites pertaining to all the other communities;
- It’s not size, it’s density. The visibility and centrality (in the online debate) of a cluster of websites should be inferred from the density of their linking pattern rather than from the size of their area on the map. For instance, a set of closely-knit websites spread over a small area displays a high density of links and enjoys good visibility. Conversely, a spread out group of websites displays a low density of links and does not enjoy good visibility on the web.
That’s it. Now you can navigate inside the Politicosphere map and analyze in detail the relations between sites and communities.