Result of Performance vector??

rresetarrresetar Member Posts: 4 Contributor I

Hello, i am pretty new in DM and Rapidminer. I looking for some help.

Can somebody help me how to explain the result of Performance vector??

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Answers

  • rresetarrresetar Member Posts: 4 Contributor I
    tnx man, really helpful 
    varunm1
  • rresetarrresetar Member Posts: 4 Contributor I
    Can you explain the meaning of class precision and class recoll i can not get the understanding ( my naitive language isnt eng)
  • varunm1varunm1 Member Posts: 719   Unicorn
    Ok, I will try to explain with a simple example.

    Think you have a dataset with 100 samples (rows) that belongs to two classes "apples" and "oranges". Here 50 samples of your data belong to apples and another 50 belongs to oranges. You trained and tested a machine learning algorithm.

    This algorithm predicted 25 samples as apples, in these 25 apple predictions 12 are really apple (based on your label) and 13 are predicted as apple actually belongs to orange in the dataset. Similarly, there are 75 predictions as oranges, in these 75 predictions  38 predictions belong to apple class but they were predicted as oranges and 37 predicted as an orange belongs to orange in the data.

    Now Recall of a class is the (the number of samples predicted as apples by an algorithm that really belong to apple class) divided by (the total number of apple samples in an algorithm) which is 12/50.

    Now class precision for apples is (the number of samples predicted as apples by an algorithm that really belong to apple class) divided by (total number of samples predicted as apple) which is 12/25.

    This is similar to the orange class as well. 

    I am also providing you with a video from rapidminer academy that helps understand these.
    https://academy.rapidminer.com/learn/video/introduction-to-performance-measurement
    lionelderkrikorTghadiallysgenzer
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