PPT-What are variables? Or what changes during experiments….

Independent Variables What is tested by the scientist What is changed by the scientist Also known as manipulated variables Dependent Variable What is observed What is measured The effect caused by the independent variable. 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.. Diana C. . Mutz. University of Pennsylvania. Analysis of Experiments. Simple, straightforward. No fancy statistical techniques required. Very few questions required. Comparison of means (analysis of variance). . 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 . Unconscious Behavior. Criteria: . Real problem. Relevant to food (health). Actionable. Best method. Best journal. Method: . Pediatrician office flu/cold patients. 2x2: . teasp. vs. . tblsp. ; kid vs. no kid. Overview. How do experiments differ from observational studies?. What are the three main variables we need to consider in experimental research?. What are the similarities and differences between between-group and within-subject experiments?. 1. Walter F. Blood. Director of Product Management . Agenda. 2. Variables – A Quick Review. Variables in Reports. Variables in Procedures. Variables in Masters. A Quick Review. 3. The Basics. 4. Two types of Variable. Research Objective. Show direct cause & effect. Study relationships among variables for existing groups. Explain outcomes after the fact. Type of Design. True Experiment. Quasi-Experiment. Cross-Sectional. 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!. Experiments. After this section, you should be able to…. DISTINGUISH observational studies from experiments. DESCRIBE the language of experiments. APPLY the three principles of experimental design. • State-space representation.. • Linear state-space equations.. • Nonlinear state-space equations.. • Linearization of state-space equations.. 2. Input-output Description. The description is valid for. Design and Analysis. STA 320. Design and Analysis of Causal Studies. Dr. Kari Lock Morgan and Dr. Fan Li. Department of Statistical Science. Duke University. Covariates. Pre-treatment variables. X: n x k covariate matrix. 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. PPAP Meeting. Birmingham. 15 July 2009. Elisabeth Falk. University of Sussex. Def. current: running or under construction. Outline. Neutrino-oscillation experiments:. what to measure, and how. Accelerator-based experiments. 8 The experiment should be conducted only by scientifically qualified persons The highest degree of skill and care should be required through all stages of the experiment of those who conduct or engag