The purpose of this tool is to allow you to search the full text of one or more items, all at once. Each page of each book has been digitized and software has been used to extract and index each word that occurs on every page, thus the term "full text". The MHL searches the full text and the descriptive information (metadata) compiled for each item (such as title, author, publication date, and subject terms). As with any digitization project, an OCR error rate of 1% is expected. Factors affecting the error rate include non-Roman typefaces and font size. By comparison, the Internet Archive search allows full text search on one item at a time. It does not offer simultaneous full text search of multiple items within the MHL. Additionally, the Internet Archive does not index every page of every text. For this reason, search results may vary between the two tools. The results from this tool are more comprehensive.
In addition to OCR errors, results are influenced by the completeness of the descriptive information (metadata) provided by the contributing libraries. We know, for example, that for 4,000 items in the MHL, no date has been provided. There is no full text for video items. Serial publications present special problems: volume numbers and volume dates are not always complete or uniformly formatted. For each volume a second date may appear ("Date"). This indicates the first year of publication.
Each field is labeled with the behavior it applies:
Note: The advanced keywords fields are purposefully designed to eliminate the need to add logical operators to your queries (AND, OR, "", (), etc.). Including these in your queries may produce undesired results.
All field-specific filters apply a phrased search limited to that field. Example: human medicine in Title contains is applied as TITLE CONTAINS "human medicine"
Facet filters such as Languages and Media Types. Simply click any facet choice to apply, click again to de-apply.
Note that facets show ONLY the available options and count for the current result set, based on the current keyword(s) search.
This tool is beta software. We need your feedback! If you are having problems using the tool or would like to suggest improvements, please contact us at email@example.com