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The People Behind Precision ABA
Brigid McCormick, MA, BCBA, LBA
Founder & Clinical Director
Brigid McCormick founded Precision ABA in 2015 and remains its sole owner and Clinical Director. She earned her bachelor’s degree in education before finding behavior analysis and Precision Teaching and has now worked in the field for 15 years.
Brigid’s areas of expertise include Precision Teaching, instructional design, complex skill development, and clinical judgment. She remains closely involved in the day-to-day work at Precision, working alongside clinicians and learners while running the practice.
Brigid also founded The Institute for Clinical Excellence at Precision ABA, where she trains and mentors behavior analysts and other professionals outside of Precision. She currently serves on the Illinois Department of Financial and Professional Regulation’s Behavior Analyst Licensing and Disciplinary Board and previously served as President of the Illinois Association for Behavior Analysis. Her work is grounded in a simple expectation: understand the learner, measure what matters, and keep changing the teaching until learning happens.
Our Leadership Team
Kevin Schneider MA, BCBA (he/him)
Business Manager and Behavior Analyst
Kevin received his Master of Arts degree in Applied Behavior Analysis from The Chicago School of Professional Psychology. Kevin wears several hats at Precision ABA, including working as a Behavior Analyst and our Business Manager. As a Behavior Analyst, Kevin enjoys working with adults with developmental disabilities, and their staff and families, on building new skills and supporting new behaviors. Kevin lives for data analysis and spends his free time working on cars, building things, and making spreadsheets.
Kelsey Lund, MS (she/her)
Director of Operations
Kelsey has been an integral part of the Precision ABA team since September 2017. She earned her Master of Science degree in Applied Behavior Analysis from The Chicago School of Professional Psychology, after graduating from North Central College with a Bachelor of Arts in Psychology.
When she’s not at work, Kelsey enjoys traveling, trying out different cuisines, reading and spending quality time with her family and friends.
Kelsey loves her job for its unique opportunities. She takes pride in supporting her team, fostering their growth, enhancing their skills, and empowering them to reach their full potential. For Kelsey, one of the best parts of her job is working alongside a team of incredibly knowledgeable, and dedicated people who genuinely care for their clients and each other. She’s continually inspired by the growth and success she sees within her team and the meaningful impact they create together.
Ennis Hajyousif, MSHA (he/him)
Practice Manager
Ennis isn't just an administrator; he knows exactly what goes into life-changing therapy. He began his journey in the ABA field as a Registered Behavior Technician, working directly with children and experiencing firsthand the daily triumphs and challenges of behavioral therapy.​
​His natural leadership and passion for systemic improvement quickly led him to the operations side of ABA, where he climbed the ranks to Operations Manager. With nearly three years in the ABA field under his belt, Ennis knows exactly what it takes to keep a clinic running smoothly so our clinical team can focus entirely on what they do best: helping kids thrive. To back up his real-world experience, Ennis holds a B.S. in Neuroscience from Northwestern University and an M.S. in Health Administration from the University of Louisville.​
Ennis is dedicated to ensuring our families and team have the seamless, supportive environment they deserve. When he’s not at work, Ennis loves traveling, anime, cooking, and getting outdoors.
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Our Clinical Team
Desiree Marsden, MS, BCBA, LBA (she/her)
Behavior Analyst
Desiree has been a member of the Precision ABA team since May 2018. She earned her Master of Science degree in Applied Behavior Analysis at The Chicago School of Professional Psychology in December 2019. She became a BCBA in May 2020.
As a Behavior Analyst and with several years of experience in Precision Teaching, Desiree enjoys seeing the progress her clients and staff make towards their goals and knowing that she played a role in getting them there. She is committed to learning and growth, believing in the importance of feedback and embracing discomfort. She is dedicated to fostering an environment where learners can be their true, authentic selves and self-advocacy is promoted. When she's not working, you can catch Desiree doing yoga, listening to music (or going to a show), going for bike rides and hikes, or spending quality time with family and friends!
Kelly is a behavior analyst and educational leader with over ten years of experience in special education and therapeutic school settings. She earned a Masters degree in Curriculum and Instruction and holds a Board Certified Behavior Analyst (BCBA) credential, blending a deep understanding of instructional practice and education with the science of behavior.
Behavior Analyst
Kelly Russell, M.Ed., BCBA, LBA (she/her)
​Kelly has spent the past decade serving students with diverse learning and behavior needs in several settings including school, clinic, and in home. She has previously held leadership roles focused on coaching teachers and direct support staff, building and overseeing systems for mentoring and professional development, and collaborating with multidisciplinary teams to ensure high quality and values-driven services. Kelly loves teaching and learning and is grateful to have found behavior analysis where she gets to do both everyday! Outside of work, Kelly likes to travel, read, crochet, and work in her garden.
Paige Tuominen (she/her)
Program Manager
​Paige has been a member of the Precision ABA team since April 2023 and currently serves as a Program Manager. She earned her Master of Arts degree in Applied Behavior Analysis in May 2026.
After joining Precision ABA, Paige developed a strong passion for both Applied Behavior Analysis and Precision Teaching. Paige values data-based decision making, continuous improvement, and fostering positive relationships that help learners succeed. Committed to lifelong growth, Paige believes that learning never stops and embraces opportunities for professional and personal development. She is dedicated to creating an environment where learners feel supported, empowered, and encouraged to reach their full potential.
When she’s not at work, Paige enjoys dancing, reading, and having fun with her friends and family!