Paul Jorgensen, Ph.D., spent his 20-year first career in all phases of software development for the research and development laboratory of a telephone switching systems company. He began his university career in 1986 teaching graduate courses in software engineering at Arizona State University, and since 1988, at Grand Valley State University where he is a full professor. Paul retired from the university in the summer of 2017 and is now a Professor Emeritus. He jokes that he has seven-day weekends, every week. This schedule permits a lot of family contact and also allows time for his consulting business, Software Paradigms. He has served on major CODASYL, ACM, IEEE, and ISTQB committees, and in 2012, his university recognized his lifetime accomplishments with its “Distinguished Contribution to a Discipline Award.” In addition to this software testing book, he is also the author of Modeling Software Behavior: A Craftsman’s Approach and The Craft of Model-Based Testing. He is a co-author of Mathematics for Data Processing (McGraw-Hill, 1970) and Structured Methods--Merging Models, Techniques, and CASE (McGraw-Hill, 1993). Living and working in Italy for three years made him a confirmed "Italophile." He, his wife Carol, and daughters Kirsten and Katia have visited friends there several times. Paul and Carol have volunteered at the Porcupine School on the Pine Ridge Reservation in South Dakota for 19 years. His preferred email addresses are jorgensp@gvsu.edu; paul@softwaretestcraft.org.

Byron DeVries, Ph.D., has taught undergraduate and graduate software engineering courses at Grand Valley State University since he joined the faculty in 2017 as an assistant professor. Prior to teaching, he spent over a dozen years in a variety of avionics software development roles, often focused on verification. He actively publishes in and serves on program committees for a variety of IEEE and ACM conferences. In 2021, he was recognized by his university with the “Distinguished Early Career Scholar Award.” In the summers, you can most often find him either close to, or on, the water around West Michigan with his wife, Angela. Though an avid sailor, he begrudgingly spends more time on power boats for the sake of his two young boys: Bryce and Wesley. You can reach him at his email addresses: devrieby@gvsu.edu and byron@softwaretestcraft.org.