# Evaluating Numeric Prediction

Hello all,

Please consider the following:

=== Summary for Numeric Class Label ===

Correlation coefficient 0.961

Mean absolute error 1.0733

Root mean squared error 1.4616

Relative absolute error 22.909 %

Root relative squared error 27.9396 %

_________________________________

How can I judge my model ?! is it good?. Correlation measure reflects good performance, but

Best Regards,

--

Motaz K. Saad

http://motaz.saad.googlepages.com

Please consider the following:

=== Summary for Numeric Class Label ===

Correlation coefficient 0.961

Mean absolute error 1.0733

Root mean squared error 1.4616

Relative absolute error 22.909 %

Root relative squared error 27.9396 %

_________________________________

How can I judge my model ?! is it good?. Correlation measure reflects good performance, but

**Relative absolute**and**Root relative squared**errors are high !Best Regards,

--

Motaz K. Saad

http://motaz.saad.googlepages.com

0

## Answers

2,531Unicornthis seems to be no overwhelming good results. Try optimizing your parameters, generate features or change learning algorithm. This could help.

If you already did, its perhabs as good as it can be. Perhabs your attributes dont catch the real dependency between label and example.

Greetings,

Sebastian

42GuruWhen Can say my model is good ????!!! ???

when Mean absolute error and Root mean squared error are less than 1 AND

Relative absolute error and Root relative squared error are less than 10% or 5% or .... for example

Is the number of instances affect the error measure values ?

I hope my question is clear !

Warm Greetings

--

Motaz

294RM Product Managementlet me mention two points:

1. Absolute errors can only be interpreted meaningfully if you have an idea of the value range of your label. This becomes clear, when you imagine a label that has a mean value of 1. A model producing an error of 1 in this setting could only be called disastrous. If the label has a mean value of, say, 10,000 an absolute error of 1 would rather be quite good. Hence, you can not clearly judge an absolute error without explicitely knowing the value range of the real label. That is in fact the reason for using relative errors.

2. Even with relative error functions you have to take a lot of aspects into account, e.g. the complexity of your learning problem, the capability of the learner to solve problems of that kind, etc. Hence, there is no dogmatic approach to which relative error you have to achieve to valuate a models as good or bad. Additionally, it of course depends on your evaluation procedure, what error should or might be acceptable.

Regards,

Tobias

42GuruThanks for your valuable points

I and working on time series dataset for temperature records for 2 years (726 instances). I know that I have insufficient dataset. Below is my class label information:

Minimum 6.254

Maximum 27.4

Mean 17.646

StdDev 5.235

I want to look for all error measures:

Can I say 1.0733, 1.4616 for Mean absolute error and Root mean squared error good result if the mean (average) value is 17.6 ?!

What is acceptable Mean absolute error and Root mean squared error for a numeric class with mean 17.6 ?

If I want to consider relative errors, what are the acceptable values ?

Worm Greetings,

--

Motaz