A sentiment is a view, opinion, feeling, intention, or emotion which has polarity. The polarity can be positive, negative, or neutral.
Basic sentimental analysis is the mining of textual data to extract subjective information from the source. This helps businesses to understand the social sentiment about their product, service, or brand based upon the monitoring of online conversations.
In this analysis, the algorithm divides the text into sentences and assigns some index of reference to them. The algorithm treats texts as Bags of Words (BOW), where the order of words, and as such the context is ignored. The original text is filtered down to only those words that are thought to carry sentiment.
In rubiscape, the Sentiment algorithms are,

• Basic Sentiment Analysis

In the task pane, click Textual Analysis, and then click Sentiment.

For more information, refer to Sentiment Analysis.