Computing has entered the era of uncertain data, in which hardware and software generate and reason about estimates. Applications use estimates from sensors, machine learning, big data, humans, and approximate hardware and software. Unfortunately, developers face pervasive correctness, programmability, and optimization problems due to estimates and many programming languages make these problems worse. We propose a new programming abstraction called Uncertain<T> embedded into languages, such as C#, C++, Java, Python, and JavaScript. With Uncertain<T>, applications that consume estimates use familiar operations for their estimates; an overloaded conditional operator to control false positives and negatives; and new operators to express domain knowledge. By carefully restricting the expressiveness, the runtime automatically implements correct statistical reasoning at conditionals, relieving developers of the need to implement or deeply understand statistics. We demonstrate substantial programmability, correctness, and efficiency benefits of Uncertain for GPS sensor navigation, approximate computing, machine learning, and xBox.

Kathryn S. McKinley is a Principal Researcher at Microsoft. She was previously an Endowed Professor of Computer Science at The University of Texas at Austin. She received her BA, MS, and PhD from Rice University. Her research interests span programming languages, compilers, runtime systems, architecture, performance, and energy. She and her collaborators have produced several widely used tools: DaCapo Java Benchmarks, TRIPS Compiler, Hoard memory manager, MMTk memory management toolkit, and Immix garbage collector. She has graduated 21 PhD students. Her awards include the ACM SIGPLAN Programming Languages Software Award; ACM SIGPLAN Distinguished Service Award; and Best & Test of time awards from ASPLOS, OOPSLA, ICS, SIGMETRICS, IEEE Top Picks, SIGPLAN Research Highlights, and CACM Research Highlights. She served as program chair for ASPLOS, PACT, PLDI, ISMM, and CGO. She is currently a CRA and CRA-W Board member. Dr. McKinley was honored to testify to the House Science Committee (Feb. 14, 2013). She and her husband have three sons. She is an IEEE and ACM Fellow.