Question: for what kind of models can we use ols
[{'answer': 'linear regression', 'provenance': [{'wikipedia_id': '1651906', 'title': 'Ordinary least squares', 'start_paragraph_id': 1, 'start_character': 128, 'end_paragraph_id': 1, 'end_character': 145, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}]