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Table 8 Used prediction accuracy measures

From: Prediction accuracy measurements as a fitness function for software effort estimation

ID

Name

Equations

1

Least absolute deviations (LAD)

\(LAD=\sum \limits _{i=1}^{n}\left| y_i-\hat{y}_i\right|\)

2

Mean absolute error (MAE)

\(MAE=\frac{1}{n}\sum \limits _{i=1}^{n}\left| y_i-\hat{y}_i\right|\)

3

Mean squared error (MSE)

\(MSE=\frac{1}{n}\sum \limits _{i=1}^{n}\left( y_i-\hat{y}_i\right) ^2\)

4

Root mean squared error (RMSE)

\(RMSE=\sqrt{\frac{1}{n}\sum \limits _{i=1}^{n}\left( y_i-\hat{y}_i\right) ^2}\)

5

Mean magnitude of relative error (MMRE)

\(MMRE=\frac{1}{n}\sum \limits _{i=1}^{n}\frac{\left| y_i-\hat{y}_i\right| }{y_i}\)

6

Median magnitude of relative error (MdMRE)

\(MdMRE=median\left( \frac{1}{n}\sum \limits _{i=1}^{n}\frac{\left| y_i-\hat{y}_i\right| }{y_i}\right)\)

7

MMRE relative to the estimate (MEMRE)

\(MEMRE\,=\,\frac{1}{n}\sum \limits _{i=1}^{n}\frac{\left| y_i-\hat{y}_i\right| }{\hat{y}_i}\)

8

MdMRE relative to the estimate (MdEMRE)

\(MdEMRE\,=\,median\left( \frac{1}{n}\sum \limits _{i=1}^{n}\frac{\left| y_i-\hat{y}_i\right| }{\hat{y}_i}\right)\)

9

R squared (\(R^2\))

\(R^2=1-\frac{\sum \limits _{i\,=\,1}^{n}\left( y_i-\hat{y}_i\right) ^2}{\sum \limits _{i=1}^{n}\left( y_i-\bar{y}\right) ^2}\)

10

Prediction within 25 % Pred(25)

\(Pred(25)=\frac{Number\;of\;projects,\;where\;(MRE\le 0.25)}{Number\;of\;projects}\)