| 1 | | The fitness of a model should be calculated only on a subset of all rows of the data set for instance by declaring a variable that indicates valid rows. This can for instance be useful in certain time series modeling scenarios. |
| | 1 | It should be possible to indicate weights for observations. |
| | 2 | Benefits: |
| | 3 | - More important data points can be weighted more strongly |
| | 4 | - Outliers can be remove by setting the weight to zero |
| | 5 | - If we know the variance for observations we can consider non-equal variances for observations |
| | 6 | - We could more easily aggregate multiple observations and put a higher weight on it (the average has less variance). |
