Subject	historian
Predicate	investigate
Object	past
Modality	Modality Occurrences
Polarity	POSITIVE
Plausibility	0.9721
Neighborhood Sigma	0.9730
Local Sigma	1.0000
Example Sentences	Sentence Occurrences Source historians investigate the past 6 Google Autocomplete, Answers.com Questions historians and archaeologists investigate the past 2 Google Autocomplete