Working on Recommendation System case study - Predicting Book rating, issue with the prediction v...

I am using the Book recommendation case study to predict the book ratings, the variable rating scale is 1-5, but when the Spark Collaborative filtering Learner node is used to learn the data and Spark Prediction(MLlib) node is used for prediction, the predicted variable value is ranging between -2.5 to 7.7.

Not able to understand why the predicted value is ranging between -2.5 to 7.7 and not between 1 to 5.

Tried normalizing the predicted variable, but still the range remais same.

Sharing the workflow for your reference, i need clarity on the predicted value.

Please do the needfull quickly

Workflow - Book Recommendation1.knwf.knwf

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