The sentiment index summarizes in a single number the distribution of sentiments across your documents. It informs you how positive or negative the sentiment is within a certain collection of documents.
To define the sentiment index, we took inspiration from the well-known Net Promoter Score (NPS). The NPS value is defined as the difference between the percentage of promoters and detractors in a dataset, and as such falls within a range between +100 and -100, with the two extremes indicating that only promoters or detractors exist in the collection. The more positive the score the happier your customers are.
We take the same approach to define the sentiment index as the difference between the percentage of segments with positive and negative sentiment in your dataset. The higher the score, the more weight lies on the positive side of your customer's sentiments.
In Deep Talk, we use the sentiment index to
track evolution of your sentiment over time
rank categories by sentiment
rank topics by sentiment
Hopefully our insights help to make your sentiment index grow over time.
Thanks for reading!