Sibyl Martha Rock (August 1, 1909 – November 17, 1981)[1][2] was an American inventor who was a pioneer in mass spectrometry and computing.

In sales, she worked closely with people at chemical and refining companies who were potential customers for the mass spectrometer and early digital computers, identifying their needs and concerns.

People such as Seymour Meyerson, who worked for Standard Oil of Indiana, were active contributors to Rock's CEC Users' Group.

[12] In 1946, with Clifford Berry, she developed an analog computer capable of solving multiple simultaneous linear equations, suitable for the analysis of data from mass spectrometers.

Feedback from the field and effective communication about needs and problems were critical to CEC's success in building and marketing mass spectrometers.

She was also a key person assisting Consolidated's customers in the use of those instruments and techniques, including the use of Cliff Berry's analog computer.

Rock continuously drew upon her knowledge of the latest methods used by customers and their critiques and problem reports about the instrumentation, to improve CEC's products.

[16] Sibyl Rock once described her work as follows: 'For the past several years I have written Product Specifications for digital computers and related peripheral gear.

Because the engineer may be too optimistic as to what he can produce and what reliability he can achieve, and because marketing wants the moon for zero dollars, the product specification writer is needed as a negotiator.

[1] In addition to the manuals she wrote, Rock was active in scholarly publishing and coauthored significant papers with several of her colleagues,[13] including: