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ENVS 355. Data, data, data Models, models, models Policy, policy, policy. In an Ideal world:. STOP; MUST DETECT THIS. Good Data. BAD, Biased, or Incomplete Data. Informs model. Biased Model. Interrogate model. Refined Evolving Model. Data Based Policy Real world behaves better.
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ENVS 355 Data, data, data Models, models, models Policy, policy, policy
In an Ideal world: STOP; MUST DETECT THIS Good Data BAD, Biased, or Incomplete Data Informs model Biased Model Interrogate model Refined Evolving Model Data Based Policy Real world behaves better Data Ignored; Bias and Anecdotes Abound Failure Points in this Process
Environmental Problems • Usually characterized by noisy/ambiguous data which can then support multiple views of the same problem Who’s right? • Difficult to model due to a) poor data constraints and b) missing information • The scientific method is usually not part of environmental policy
Course Goals • To give students experience in these three intertwined difficulties • To develop student data analysis and presentation skills so that you can become worthwhile in the real world • To learn how to use a computer to assist you in data analysis and presentation • To give students experience in project reporting
More Goals of this Course • To gain practice in how to frame a problem • To practice making toy models involving data organization and presentation • To understand the purpose of making a model • To understand the limitations of modeling and that models differ mostly in the precision of predictions made • Provide you with a mini tool kit for analysis
Course Content • Introduction to various statistical tools, tests for goodness of fit, etc. • To understand sparse sampling and reliable tracers • To construct models with predictive power and to assess the accuracy of those models • To learn to scale in order to problem solve on the fly
Probable Topics • Predator-Prey Relations and statistical equilibrium • Population projects and demographic shifts • Measuring global and local climate change • Resource depletion issues and planning • Indicators of potential large scale climate change • Vehicle Mix in Eugene
Sequence for Environmental Data Analysis • Conceptualization of the problem which data is most important to obtain • Methods and limitations of data collection know your biases • Presentation of Results => data organization and reduction; data visualization; statistical analysis • Comparing different models
Some Tools • Linear Regression predictive power lies in scatter your never told this! • Slope errors are important your never told this either! • Identify anomalous points by sigma clipping (1 cycle) • Learn to use the regression tool in Excel • Graph the data always no Black Boxes
More Tools • Chi square test – is your result different than random? • Chi square statistic - Know how to compute it and what it means • Comparing statistical distributions to detect significant differences • Advanced Methods (KS Test most powerful but not widely used) • Discrete/arrival statistics (Poisson statistics) • Data visualization very important
Estimation Techniques • Extremely useful skill makes you valuable • Devise an estimation plan what factors do you need to estimate e.g. how many grains of sand are there in the world? • Scale from familiar examples when possible • Perform a reality check on your estimate