NSI, Inc. National Security Innovations | 535 followers on LinkedIn. NSI is a professional services firm specializing in multidisciplinary data-driven analytics. Our niche is helping clients better and more reliably understand people and their behaviors on critical, complex decision-making problems. Our highly diverse and experienced team of researchers and analysts apply multidisciplinary social science techniques and various analytic methods to create deeper analyses and clarifying insights enabling our clients to make more informed and better decisions.