TITLE: Interactive Data Analysis ABSTRACT: In this talk, I will discuss our research on interactive systems for data cleaning, assessment and exploration. Collectively, these systems contribute new approaches for improving the efficiency and scale at which expert analysts work, while lowering the threshold for non-experts. Data analysts often expend an inordinate amount of effort manipulating data and assessing data quality issues. With our Wrangler system, users construct data transformation scripts in a direct manipulation interface. Wrangler uses programming-by-demonstration methods to automatically suggest applicable transforms and preview their output. The end result is not simply transformed data, but a reusable program that can be run at scale. Once data has been suitably transformed, our Profiler system combines anomaly detection and automatic visualization recommendations to aid quality assessment. Next, I will describe imMens, a system for real-time visual querying of big data. To enable visual analysis at scale, imMens follows the principle that perceptual and interactive scalability should be limited by the chosen resolution of the visualized data, not the number of records. Using a combination of multivariate data tiles and client-side parallel query processing, imMens supports 50 frames-per-second linked selection across summary visualizations of data sets ranging from thousands to billions of records.