Sentiment
Sentiment is a statistic that IKANOW captures on a per entity/query basis and which refers to the perceived positive or negative feeling around a specific entity. Sentiment can also capture the positive or negative relationship between two entities.
Source Configuration
IKANOW does not have its own positive/negative sentiment engine, and instead plugs into some of the more popular sentiment services available such as Alchemy API and OpenCalais. The selection of sentiment is done during source configuration, by configuring the source pipeline accordingly.
Sentiment Calculations
For each entity comprised by the query, IKANOW attaches a sentiment calculation based on the commercial service plugged in, which can range from 0-1. This measures the entity extraction engine's "opinion" on whether the document refers to the entity approvingly (positive, <= 1.0) or disapprovingly (negative, >= -1.0). On the per query level, several relevant statistics/metrics are captured. "averageFreq" captures the (approximate) average frequency (including documents in which the entity doesn't appear) across all documents that match the query. "positiveSentiment" is the sum of the positive sentiment counts across the matching documents, while "negativeSentiment" is the sum of the negative sentiment counts across the matching documents. "sentimentCount" is the total number of sentiment counts (positive or negative) across the matching documents. This equates with the positive/negative aggregate sentiment metrics which are rolled-up to the widgets.
Widgets are a great way to visualize the statistics/metrics that are returned by the Community Edition platform in response to a query. The Sentiment Widget widget captures positive, negative and aggregate sentiment and dispalys it on a graph with query coverage, query significance and average frequency.