Intro to Sentiment Analysis: What it is, how to conduct it, and what are its limitations?
1. What are they saying?
Sentiment Analysis
Professor Matthew Kushin, PhD
Shepherd University | Department of Mass Communication | 2012
2. Preview
Last class:
Looked at what people say about a brand online
Today, we’ll explore:
Can we more systematically evaluate text content (such as
tweets)?
3. Defined
Sentiment analysis – process of categorizing text, based on
the “sentiment” or “feelings” embedded in the message.
Aka “opinion mining”
For assessing opinions
Form of content analysis – systematic process of coding
content of media for interpretation
4. Simple Example
Tweet:
“Can’t wait to see Zan the Ram at the game this weekend!!!”
Sentiment:
Positive
Problem
How do we know that this text is positive?
5. Basics: How it works
A database of words and symbols (e.g., !) is created.
Each word is assigned a value
Positive = 1
Negative = -1
Neutral = 0
Example: “love” = 1; “hate” =2; “blue” =0
6. How it works, contd
Computers or person evaluates each piece of data (e.g., a
Tweet), searching for words in database.
Total number of positive/negative/neutral counted in data,
and a sentiment score or % is given
7. Example
Tweets about Shepherdstown over a one-week period:
60% positive
20% negative
20% neutral
9. Potential, potential
Attitude towards your brand
Perception of products, ideas, brands, people, etc.
Reputation management
Able to respond to posts
Evaluate over time to see if sentiment is changing as part of
campaign goals
10. Example: Taco Bell Beef!
Last class
an unrepresentative sample of Tweets we happen to look at
Sentiment offers:
Much more systematic evaluation of tweets
Evaluate thousands of social media posts
Very quick & little cost
12. Tools
Many tools (paid and free) exist for assessing sentiment
Study of linguistics is applied backed by years of research &
understanding of human language.
Common limitations:
Language contains context
Is subjective
Inability to assess sarcasm & other nuances of human
communication
14. Key Considerations
We must interpret what the sentiment means
Sentiment alone is only a minor indicator of the true feelings
of the crowd.
Need to ask “Why is it positive/negative?”
“What products do people mention?”
15. Beyond Basic Sentiment
Computer-assisted content analysis of social media posts
virtually limitless potential
More detail than “pos” “neg” “neutral”
What about:
“satisfied” “dissatisfied” “concerned” “informed” “afraid” “glad”
etc.
Count all mentions of ANY term
Ex: product mentions in tweets: “Fries” “McRib” “McFlurry”
16. Participation: Obama v. Romney
Sentiment
Getting the PDF files:
Obama Tweets PDF: http://bit.ly/402_ObamaTweets
Romney Tweets PDF: http://bit.ly/402_RomneyTweets