Which is more robust against outliers: mean or median? This app demonstrates the (in)stability of these descriptive statistics as the value of an outlier and the number of data points change.
Which is more robust against outliers: mean or median? This app demonstrates the (in)stability of these descriptive statistics as the value of an outlier and the number of data points change.
Approximating a normal distribution with a binomial distribution
This page supports an in-class exercise that highlights several key Bayesian concepts. The scenario is as follows: a large paper bag contains pieces of candy with wrappings of different color, and we are interested in learning about the unknown proportion of yellow-wrapped pieces of candy. After completing the exercises, we will be familiar with the following concepts and ideas: probability distributions can quantify degree of belief, prior distribution, posterior distribution, sequential updating, conjugacy, Cromwell’s Rule (http://en.wikipedia.org/wiki/Cromwell's_rule), the data overwhelm the prior, Bayes factors, Savage-Dickey density ratio, sensitivity analysis, coherence.
Adjust regression parameters to bend and shift a two-dimensional polynomial surface.
The Global Terrorism Database (GTD) contains information about more than 140,000 terrorist incidents occurring between 1970 and 2014. The data in the GTD are gathered from information gathered through multiple news sources (LaFree, Dugan, & Miller, 2015). In this activity, we will study the extent to which chemical, biological, radiological, and nuclear (CBRN) weapons have been used so far. We analyze whether or not their past use fits with our perceptions. Have CBRN weapons been used successfully in the past? Which weapons are more historically dangerous (more fatalities, injuries) in the hands of terrorists? What are the implications of past usage of CBRN weapons compared to other weapons in determining our priorities in counter-terrorism policies?
The NYPD lab uses interactive, online graphs to better understand patterns in stop and arrest data for the New York Police Department. These data were originally collected by New York Police Department officers and record information gathered as a result of stop question and frisk (SQF) encounters during 2006. These data were used in a study carried out, under contract to the New York City Police Foundation, by the Rand Corporation's Center on Quality Policing. The release of the study, "Analysis of Racial Disparities in the New York Police Department's Stop, Question, and Frisk Practices" (Rand Document TR-534-NYCPF, 2007) generated interest in making the data available for secondary analysis. This data collection contains information on the officer's reasons for initiating a stop, whether the stop led to a summons or arrest, demographic information for the person stopped, and the suspected criminal behavior."
The Military Spending lab uses interactive, online graphs to better understand total military spending for each country. We see the limitations of traditional histograms and also consider the importance of using appropriate scales when comparing countries. The emphasisis of this lab is on understanding the impact of appropriate data transformations and data visualizations.
App: http://shiny.grinnell.edu/Military_Spending_Basic/
Handout: http://web.grinnell.edu/individuals/kuipers/stat2labs/Handouts/MilSpendB...
Learn to distinguish between exponential and logistic growth of populations, identify carrying capacity, differentiate density-dependent and density-independent limiting factors, apply population models to data sets and determine carrying capacity from population data. Make predictions on graphs and interpret graphical data to analyze factors that influence population growth.
This link includes a lesson plan, assessment materials, and access to SmartGraphs, a software that helps students create and interpret graphs.
This website provides a comprehensive overview of descriptive statistics (mean/median/mode, range, standard deviation, and variance) through informative webpages with examples, links to data sets, and problems for the readers to try for themselves.
Statistics forum for questions/conversations ranging from homework problems in statistics and probability and help using statistical software to statistical research inquiries and career advising.