Synopsis of Proposed Contract Action: NSF intends to award a purchase order on a sole source basis to Clarivate for Custom Data Extract - Web of Science - XML - Custom With Updates. This data includes metadata from over 12,500 journals spanning over 250 science, social science and humanities disciplines. Conference proceedings and book metadata are also available. Data are available back to 1900 and include over 63 million article records and 1 billion cited references to date. This notice of intent is not a request for competitive proposals. This synopsis is for informational purposes only. Market research and technical validation confirm that this specific proprietary commercial software license is essential to the Government's requirement. Similar commercial products or alternative platforms cannot be modified to meet agency operational parameters without substantial duplication of cost to the Government that is not expected to be recovered through competition per RFO FAR 6.302-1(a)(2)(ii)(A). Under RFO policy, the statutory exception applies that only one responsible commercial source can satisfy the Government requirement.