Language is an interesting and innately human thing. Language transcends the spoken word and involves vocal inflection, facial expressions and other forms of body language. Growing up, my mother could give me “the look” and I knew exactly what she was trying to say, even without words. “The look” told me to straighten up and fly right or face the consequences!
Given all of those elements, it becomes less challenging to figure out what the people around us are trying to say, but we, as people, still don’t always get it right. How often have you been talking to a spouse or loved one and had your words or intentions completely misunderstood? It happens all the time, even with the visual and auditory cues.
The challenges grow when the visual and auditory cues are taken out of the mix and language is converted to text. Unless you are the person who wrote the review, filled out the survey or tweeted the Tweet, no one can really say with 100% accuracy what the true sentiment or intention is.
Consider these examples with inserted auditory and visual cues:
PFFT! I love that product. <with an eye roll>
Or
Woah! I love that product! <with an open armed gesture and quick raise of the eyebrows>
The first example is probably sarcastic, and the person probably doesn’t really love the product. The second might be genuine with the person being a fan of the product.
Now consider the written sentence:
I love that product.
Does the person really love the product? With no other context it can be hard to tell. Maybe if there were an exclamation point at the end, we could make the leap that the person was being sincere, but in reality, without the context, we don’t really know.
As organizations take steps to fully analyze the voice of the customer using sentiment analysis tools, the question on accuracy always comes up. Everyone wants to talk about the numbers. Here’s one take on the numbers.
It’s estimated that a professionally trained linguist can accurately assess sentiment on unstructured text 80% of the time. Although there are incredible benefits to automating text analysis, an automated process without human intervention, even with stellar natural language processing, is not going to do better than a professionally trained human.
With 80% accuracy as our baseline, let’s take a look at numbers that I often see bandied about—85%, 95%, 99%. But are they really getting higher accuracy rates than a linguist? They might be overtraining their models. They may be talking about 85%, 95% or 99% of the 80%. I hate to say it, but like language, accuracy numbers are also open to interpretation!
A hybrid approach to sentiment analysis unites the power of statistical learning with advanced linguistic methods to home in on the sentiment buried within textual data. This is proven to provide more accurate sentiment analysis results. You have the best of both worlds--the unbiased statistics and the human validation.
The initial steps in beginning sentiment analysis can be daunting. There’s so much data available (survey, call center, social media, etc.). Where do you start?
Methodologies need to be explored. Should we try to assess sentiment on individual documents? Does that give us valuable information? Should we look at larger collections of documents?
If we place our focus on every individual survey or tweet in an effort to assess sentiment, the results could be overwhelming. There are as many opinions and ideas as there are individuals. A more widely accepted approach is to look at an overall collection of documents, for trends. There might be certain thought leaders or influencers you will want to analyze on an individual basis, but from a voice of the customer standpoint, looking at the bigger picture can provide more insights.
Software automates a good portion of sentiment analysis
The value software brings to the table with regards to sentiment analysis is the ability to automate a good portion of the work. Just having people (in most cases, not linguists) reading through verbatims can be fraught with challenges. Because we all have our own experiences and biases, what may seem positive to me, may not seem positive to you. The interpretations of a team of readers can introduce additional error and confusion. The volume is so great that one person can’t read it all, so automated methods of assessing sentiment truly are necessary.
Software approaches still require initial human involvement in order to ensure accuracy and get the most appropriate results. Demographics and subject matter expertise often come into play. My dad is a baby boomer who restores classic Corvettes. When he uses the word “boss”, he uses it as an adjective to mean that something is really good. When I use the word “boss”, more often than not, I’m using it as a noun referencing my manager. If I know my data is related to baby boomer car guys, I can adjust my models appropriately to capture “boss” with positive tonality rather than a neutral noun. Human intervention is also required to validate and refine the models. Over time, the amount of human intervention required decreases. It’s an iterative process that becomes much less manual as it matures.
There’s no easy button approach to assessing sentiment, and often there are no concrete “right” answers. In order to best gauge how your customers feel about products or services, it becomes necessary to spend some time understanding how your customers communicate—not only looking at the different “voice of the customer” sources, but also looking at their colloquialisms or jargon. The work involved in gaining better insights into who your customers are, can pay off in dividends—better, more self-sufficient models over time. Better models will yield answers that are more “right”. Those answers can provide your organization with information that people in your organization can trust and act upon.
Richard Foley, the product manager for SAS Text Analytics has written a blog regarding precision versus accuracy: http://blogs.sas.com/content/text-mining/2011/01/21/precision-over-accuracy/
Write and let me know your experiences with sentiment analysis precision versus accuracy.
One final note, sentiment analysis is a key topic at Text Analytics World in San Francisco. http://www.textanalyticsworld.com/
Kathy Lange of SAS is presenting the latest in high-performance analytics on March 7.