PPT-Rerandomization in Randomized Experiments

Kari Lock and Don Rubin Harvard University JSM 2010 The Gold Standard Why are randomized experiments so good They yield unbiased estimates of the treatment effect They eliminate confounding factors. Randomiza tion if done properly can keep study groups as similar as possible at the outset so that the investigators can isolate and quantify the effect of the interventions they are studying No other study design gives us the power to balance unkno The tradeoff between internal and external validity. Natural sciences. In natural sciences, most experiments have been undertaken in carefully controlled laboratory conditions. Seeking laws of physics, etc.. CS648. . Lecture 3. Two fundamental problems. Balls into bins. Randomized Quick Sort. Random Variable and Expected . value. 1. Balls into BINS. Calculating probability of some interesting events. 2. CS648. . Lecture 6. Reviewing the last 3 lectures. Application of Fingerprinting Techniques. 1-dimensional Pattern matching. . Preparation for the next lecture.. . 1. Randomized Algorithms . discussed till now. Gary Simpson. University of the West of Scotland. Fast-timing from below isomers ion-. g-g. Use selectivity of spectrometer + isomer decay. Know what isomer is. . 1. . 2. T. 1/2. . start. stop. Experimentation . Experiments and Torture. Some of the information is taken from Nazi Human Experimentation. Human Experimentation . Experiments on twins. Bone, muscle, limb and nerve transplant . Freezing experiments. Listening . to the Customers, not to the . HiPPO. Ronny Kohavi, . General Manager. Experimentation Platform, Microsoft. ronnyk@microsoft.com. . The Analytics . Revolution, Apr 2010. , . SDForum. 2. Amazon . . True Experiments. Characteristics. Threats to validity controlled by experiments. Threats not controlled by experiments. Obstacles to true experiments in the field. . Quasi-experiments. The logic of quasi-experiments . By. Ajinkya. . Thorve. Introduction. Advancement of tracking technologies has lead to increased data collection.. Collected data used, sold and resold for serving targeted advertisements.. Serious privacy concern!. RELATED TO NUCLEAR DATA. FOR FAST REACTOR APLICATIONS. DEN/CAD/DER/SPRC/. LEPh. . |. . Pierre Leconte. , David Bernard. , Cyrille de Saint Jean. DEN/. CAD/. DER/. SPEx. /LPE . |. Patrick Blaise, Benoit . Experiments and Observational Studies. 1/23/12. Association. versus Causation. Confounding Variables. Observational Studies . vs. Experiments. Randomized Experiments. Section 1.3. Professor Kari Lock Morgan. Ronny Kohavi, Microsoft. Slides available at . http://exp-platform.com. Part 1. 2. Amazon . Shopping Cart . Recs. Add an item to your shopping cart at a website. Most sites show the cart. At Amazon, Greg Linden had the idea of showing recommendations based on cart items. Quantitative Engineering Approaches. What do we know?. How do we design experiments and scale ?. Implications. Nothing except parameters we can vary. Statistical Experimental Design . Lots of experiments at all scales. Bradley Jones. Distinguished Research Fellow. JMP Division/SAS. Outline. Introduction. Textbook Designs – restrictions and limitations. Examples of Computer Generated Designs. When the region of interest is not regular.