# Estimator
The Estimator interface is implemented by all learners in Rubix ML. It provides basic inference functionality through the `predict()` method which returns a set of predictions from a dataset. Additionally, it provides methods for returning estimator type and data type compatibility declarations.

### Make Predictions
Return the predictions from a dataset containing unknown samples in an array:
```php
public predict(Dataset $dataset) : array
```

```php
$predictions = $estimator->predict($dataset);

print_r($predictions);
```

```php
Array
(
    [0] => married
    [1] => divorced
    [2] => divorced
    [3] => married
)
```

!!! note
    The return value of `predict()` is an array containing the predictions in the same order that they were indexed in the dataset.