System Observability
Apdex Alliance. “Application Performance Index – Apdex Technical Specification, Version 1.1.” 22 Jan. 2007,
https://www.apdex.org/wp-content/uploads/2020/09/ApdexTechnicalSpecificationV11_000.pdf.
Ewaschuk, Rob, “Monitoring Distributed Systems.” Chapter 6 in Site Reliability Engineering (SRE) book, Google
https://sre.google/sre-book/monitoring-distributed-systems/.
User Observability
Sauro, Jeff. “10 Essential Usability Metrics.” Measuring U, 30 Nov. 2011,
https://www.measuringu.com/essential-metrics.
Tullis, Tom and Albert, William. Measuring the User Experience. Morgan Kaufmann, 2013.
Business Observability
Morgan, Blake. “The 20 Best Customer Experience Metrics For Your Business.” Forbes, 29 July 2019,
https://www.forbes.com/sites/blakemorgan/2019/07/29/the-20-best-customer-experience-metrics-for-your-business.
Boon, Corine. “How to measure employee experience?” AIHR,
https://www.analyticsinhr.com/blog/how-to-measure-employee-experience.