Question: who is credited with promoting the use of factor analysis and why
[{'answer': 'Charles Spearman', 'provenance': [{'wikipedia_id': '253492', 'title': 'Factor analysis', 'start_paragraph_id': 94, 'start_character': 0, 'end_paragraph_id': 94, 'end_character': 16, 'bleu_score': 1.0, 'section': 'Section::::In psychometrics.:History.\n'}]}, {'provenance': [{'wikipedia_id': '253492', 'title': 'Factor analysis', 'start_paragraph_id': 94, 'start_character': 0, 'end_paragraph_id': 94, 'end_character': 497, 'bleu_score': 0.9748377259086851, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 6772988822533579323}, 'section': 'Section::::In psychometrics.:History.\n'}]}]