Certainty meaning in Duine framework

Question

I am using Duine for implementing Collaborative filtering/social filtering in java.There are 2 parameters that are given to th predictors viz., Prediction Value and Certainty.I understand that prediction value is the rating of an item by a particular user, but I am unable to understand the importance of "certainty".How does it affect the prediction? Also I just want to use One parameter i.e Prediction Value for my application.Any help is appreciated.

Answer 1

While I don't know Duine, from the naming, I'm pretty sure this expresses a degree of confidence that the predicted value is correct or accurate. A prediction of 4, and a low certainty, means the real value can only be said to be somewhere between 2.5 and 5, whereas a high confidence might express that the real value is almost surely between 3.9 and 4.1.