Exploring concept maps

You can create a concept map to explore how concepts are interrelated. By selecting a single concept and clicking Map, a concept map window opens so that you can explore the set of concepts that are related to the selected concept. You can filter out which concepts are displayed by editing the settings such as which types to include, what kinds of relationship to look for and so on.

Important: Before a map can be created, an index must be generated. This may take several minutes. However, once you have generated the index, you do not have regenerate it again until you re-extract. If you want the index to be generated automatically each time you extract, select that option in the extraction settings. See the topic Extracting data for more information.
Figure 1. A concept map for the selected concept
A concept map for the selected concept

To View a Concept Map

  1. In the Extraction Results pane, select a single concept.
  2. In the toolbar of this pane, click the Map button. If the map index was already generated the concept map opens in a separate dialog. If the map index was not generated or was out of date, the index must be rebuilt. This process may take several minutes.
  3. Click around the map to explore. If you double-click a linked concept, the map will redraw itself and show you the linked concepts for the concept you just double-clicked.
  4. The top toolbar offers some basic map tools such as moving back to a previous map, filtering links according to relationship strengths, and also opening the filter dialog to control the types of concepts that appear as well as the kinds of relationships to represent. A second toolbar line contains graph editing tools. See the topic Using Graph Toolbars and Palettes for more information.
  5. If you are unsatisfied with the kinds of links being found, review the settings for this map show on the right side of the map.

Map Settings: Include Concepts from Selected Types

Only those concepts belonging to the selected types in the table are shown in the map. To hide concepts from a certain type, deselect that type in the table.

Map Settings: Relationships to Display

Show co-occurrence links If you want to show co-occurrence links, choose the mode. The mode affects how the link strength was calculated.

  • Discover (similarity metric). With this metric, the strength of the link is calculated using more complex calculation that takes into account how often two concepts appear apart as well as how often they appear together. A high strength value means that a pair of concepts tend to appear more frequently together than to appear apart. With the following formula, any floating point values are converted to integers.
    Figure 2. Similarity coefficient formula
    Similarity coefficient formula

    In this formula, CI is the number of documents or records in which the concept I occurs.

    CJ is the number of documents or records in which the concept J occurs.

    CIJ is the number of documents or records in which concept pair I and J co-occurs in the set of documents.

  • Organize (document metric). The strength of the links with this metric is determined by the raw count of co-occurrences. In general, the more frequent two concepts are, the more likely they are to occur together at times. A high strength value means that a pair of concepts appear together frequently.

Show other links (confidence metric). You can choose other links to display; these may be semantic, derivation (morphological), or inclusion (syntactical) and are related to how many steps removed a concept is from the concept to which it is linked. These can help you tune resources, particularly synonymy or to disambiguate.For short descriptions of each of these grouping techniques, see Advanced linguistic settings

Note: Keep in mind that if these were not selected when the index was built or if no relationships were found, then none will be displayed. See the topic Building Concept Map Indexes for more information.

Map Settings: Map Display Limits

Apply extraction results filter. If you do not want to use all of the concepts, you can use the filter in the extraction results pane to limit what is shown. Then select this option and IBM® SPSS® Modeler Text Analytics will look for related concepts using this filtered set. See the topic Filtering Extraction Results for more information.

Minimum strength. Set the minimum link strength here. Any related concepts with a relationship strength lower than this limit will be hidden from the map.

Maximum concepts on map. Specify the maximum number of relationships to show on the map.