purl.org/peter.turney

Semantic Orientation - Applications

Definition of Semantic Orientation

The evaluative character of a word is called its semantic orientation. Positive semantic orientation indicates praise ("honest", "intrepid") and negative semantic orientation indicates criticism ("disturbing", "superfluous"). Semantic orientation varies in both direction (positive or negative) and degree (mild to strong).

Classifying Reviews

Semantic orientation may be used to classify reviews (for example, movie reviews or automobile reviews) as positive or negative. A review can be classified based on the average semantic orientation of phrases in the review that contain adjectives and adverbs.

Distinguishing Antonyms from Synonyms

Both synonyms and antonyms typically have strong semantic associations, but synonyms generally have the same semantic orientation, whereas antonyms have opposite orientations. For example, the words "love" and "hate" are strongly statistically associated (they tend to co-occur), but they have opposite semantic orientiations.

Summary Statistics for Search Engines

Given the query "Paris travel review", a search engine could report, "There are 5,000 hits, of which 80% are positive and 20% are negative." The search results could also be sorted by average semantic orientation, so that the user could easily sample the most extreme reviews.

New Types of Queries for Search Engines

The user could include the desired semantic orientation in the query, "Paris travel review orientation: positive".

Summarization of Reviews

A positive review could be summarized by picking out the sentence with the highest positive semantic orientation and a negative review could be summarized by extracting the sentence with the lowest negative semantic orientation.

Filtering Flames for Newsgroups and Mailing Lists

There could be a threshold, such that a newsgroup message is held for verification by the human moderator when the semantic orientation of any word in the message drops below the threshold.

Sentiment Timelines

Variation in semantic orientation in online dicussions can be plotted over time. For example, a system could track online discussions about movies and display a plot of the number of positive sentiment and negative sentiment messages over time. Advertisers could track advertising campaigns, politicians could track public opinion, reporters could track public response to current events, and stock traders could track financial opinions.

Chatbots

Semantic orientation could be used in an automated chat system (a chatbot), to help decide whether a positive or negative response is most appropriate. Similarly, characters in software games would appear more realistic if they responded to the semantic orientation of words that are typed or spoken by the game player.

Survey Analysis

Another application is the analysis of survey responses to open ended questions.

Updated: February 3, 2007.