What is LIWC?
Linguistic Inquiry and Word Count (LIWC) is a text analysis software program designed by James W. Pennebaker, Roger J. Booth, and Martha E. Francis. LIWC calculates the degree to which people use different categories of words across a wide array of texts, including emails, speeches, poems, or transcribed daily speech. With a click of a button, you can determine the degree any text uses positive or negative emotions, self-references, causal words, and 70 other language dimensions.
The LIWC program can analyze hundreds of standard ASCII text files or Microsoft Word documents in seconds. The LIWC2007 program also allows you to build your own dictionaries to analyze dimensions of language specifically relevant to your interests. The Macintosh version of LIWC2007 has a feature that will highlight in color all the words found in a particular file when it is analyzed. With the Macintosh version, users can also create dictionaries that include literal phrases (e.g. 'you know') as well as individual words and word stems.
The student version of LIWC, LIWClite7, only analyzes plain text files using the LIWC2007 and earlier LIWC2001 dictionaries. LIWClite7 is the student version that is ideal for people with limited text analysis needs.
A single-user license for LIWC2007 or LIWClite7 entitles you to install the software on no more than two computers, however discounts available for multi-user versions (see End User License Agreement here).
Macintosh versus Windows LIWC2007
Note that the Macintosh version of LIWC2007 has some features (e.g. the ability to detect phrases) that are not currently available on Windows LIWC2007. In case you may need some of these features, click here to check these before you purchase. (Note that the current version of LIWC does not work with Macintosh OSX 10.10 Yosemite.)
To learn more about the development and uses of LIWC, click the 'How it Works' link in the menu above. You can also read more about the categories and dictionary features of the LIWC2007 dictionary by clicking this link.