Since ELAN 4.7, you are able to do an N-Gram analysis over multiple eaf files. This functionality has been developed by Larwan Berke, you can find an extensive PDF document about this implementation on the third-party resources page of ELAN: https://archive.mpi.nl/tla/elan/thirdparty

When you first open the N-gram analysis, a new dialog window will pop up that contains the various options for the search and the resulting table showcasing a few statistics.

Figure 155. N-Gram Analysis dialog

The first step is to select the search domain, see the section called “How to select multiple files”. Once that is done a list of tiers seen in the domain will be shown. A note of caution: the code assumes that all files in the domain will contain the same tiers. It then loads the first file in the domain to extract the tiers and display it in the window. Check the tiers you want to analyse.

Figure 156. N-Gram Analysis dialog 2

Next, define the N-gram size in the text box. The software can handle any positive size greater than 1. When set, clicking the “Update Statistics” button will start the search and will calculate the statistics. The annotations are extracted from the files, N-grams created from them, and finally collated into groupings of same N-grams for statistical analysis. When done, you will see a pop-up window with a process report. If there were any errors, they will also be displayed here.

Figure 157. N-Gram Analysis process report

When the search is done, the result table will be displayed in the main window. Some of the columns from the data are visible here, however only a small subset is displayed simultaneously to avoid overcrowding the GUI. The visible columns are: N-gram, Occurrences, Average Duration, Minimal Duration, Maximal Duration, Average Annotation Time, and Average Interval Time.

Figure 158. N-Gram Analysis dialog 3

The first column shows the N-gram. The vertical marker “|” separates the annotations contained in the bigram. For example, if a trigram was selected it would show something similar to “FINISH|READ|BOOK” and so on for larger N-gram sizes.

Finally, in order to see the entire data that was produced it is necessary to export the results into a text file for further processing. This is done by clicking on the “Save” button and a dialog will pop up asking the user where to save the data. It is exported in a CSV-like format (Comma-Separated Values). The CSV file uses tabs “\t” as the delimiters and newlines “\n” as the record separators to avoid ambiguity with the values. A sample row is: “HOLD|IX-1p\t7.9934\t0.348\t0.13754 ...” and contains numerous columns.

Furthermore, it is possible to export the N-grams individually in order to process it separately from ELAN. The data is exported by clicking the “Raw Data” button in the GUI. After supplying the file the data will be exported in the same CSV format as discussed above. For more in-depth information about the N-Gram analysis function and the resulting data, please consult the PDF mentioned earlier on the ELAN website, or consult it here: https://parasol.tamu.edu/dreu2013/Berke/images/DREU_Final_Report.pdf (This link may become outdated at some point).