Classification Metrics

STT

Metric

Metric Fullname

Characteristics

1

PS

Precision Score

Higher is better (Best = 1), Range = [0, 1]

2

NPV

Negative Predictive Value

Higher is better (Best = 1), Range = [0, 1]

3

RS

Recall Score

Higher is better (Best = 1), Range = [0, 1]

4

AS

Accuracy Score

Higher is better (Best = 1), Range = [0, 1]

5

F1S

F1 Score

Higher is better (Best = 1), Range = [0, 1]

6

F2S

F2 Score

Higher is better (Best = 1), Range = [0, 1]

7

FBS

F-Beta Score

Higher is better (Best = 1), Range = [0, 1]

8

SS

Specificity Score

Higher is better (Best = 1), Range = [0, 1]

9

MCC

Matthews Correlation Coefficient

Higher is better (Best = 1), Range = [-1, +1]

10

HL

Hamming Loss

Higher is better (Best = 1), Range = [0, 1]

11

LS

Lift Score

Higher is better (Best=+inf), Range = [0, +inf)

12

GINI

Lift Score

Higher is better (Best=+inf), Range = [0, +inf)

13

LS

Lift Score

Higher is better (Best=+inf), Range = [0, +inf)

In extending a binary metric to multiclass or multilabel problems, the data is treated as a collection of binary problems, one for each class. There are then a number of ways to average binary metric calculations across the set of classes, each of which may be useful in some scenario. Where available, you should select among these using the average parameter.

  • “micro” gives each sample-class pair an equal contribution to the overall metric (except as a result of sample-weight). Rather than summing the metric per

class, this sums the dividends and divisors that make up the per-class metrics to calculate an overall quotient. Micro-averaging may be preferred in multilabel settings, including multiclass classification where a majority class is to be ignored. Calculate metrics globally by considering each element of the label indicator matrix as a label.

  • “macro” simply calculates the mean of the binary metrics, giving equal weight to each class. In problems where infrequent classes are nonetheless important,

macro-averaging may be a means of highlighting their performance. On the other hand, the assumption that all classes are equally important is often untrue, such that macro-averaging will over-emphasize the typically low performance on an infrequent class.

  • “weighted” accounts for class imbalance by computing the average of binary metrics in which each class’s score is weighted by its presence in the true data sample.

  • None: will return an array with the score for each class.