Another quick extension method to help with getting a sentiment score from a RecognizerResult;
public static double? GetSentimentScore(this RecognizerResult luisResult) { double? result = null; if (luisResult != null) { var data = luisResult.Properties["sentiment"]; var sentimentValues = data as IDictionary; var score = sentimentValues["score"] as JValue; result = (double)score.Value; } return result; }