SOCR EduMaterials Activities RNG
SOCR Educational Materials - Activities - SOCR Random Numner Generation (RNG) Activity
This activity describes the need, the general methods for random number generation and the SOCR utilities for simulation and random sampling. SOCR Modeler allows interactive sampling from any SOCR Distribution. This similated data may easily be copied and pasted in different SOCR Analyses or Graphing tools for further interrogation.
- Goals: The aims of this activity are to
- motivate the need for robust random number generators
- to illustrate how to use the SOCR random number generators
- to present applications of random number generation
- The SOCR CLT Experiment: To start the this Experiment, go to SOCR Experiments and select the SOCR Sampling Distribution CLT Experiment from the drop-down list of experiments in the left panel. The image below shows the interface to this experiment. Notice the main control widgets on this image (boxed in blue and pointed to by arrows). The generic control buttons on the top allow you to do one or multiple steps/runs, stop and reset this experiment. The two tabs in the main frame provide graphical access to the results of the experiment (Histograms and Summaries) or the Distribution selection panel (Distributions). Remember that choosing sample-sizes <= 16 will animate the samples (second graphing row), whereas larger sample-sizes (N>20) will only show the updates of the sampling distributions (bottom two graphing rows).
- Experiment 1: Expand your Experiment panel (right panel) by clicking/dragging the vertical split-pane bar. Choose the two sample sizes for the two statistics to be 10. Press the step-button a few of times (2-5) to see the experiment run several times. Notice how data is being sampled from the native population (the distribution of the process on the top). For each step, the process of sampling 2 samples of 10 observations will generate 2 sample statistics of the 2 population parameters of interest (these are defaulted to mean and variance). At each step, you can see the plots of all sample values, as well as the computed sample statistics for each parameter. The sample values are shown on the second row graph, below the distribution of the process, and the two sample statistics are plotted on the bottom two rows. If we run this experiment many times, the bottom two graphs become the histograms of the corresponding sample statistics. If we did this infinitely many times these two graphs become the sampling distributions of the chosen sample statistics (as the observations/measurements are independent within each sample and between samples). Finally, press the Refresh Stats Table button on the top to see the sample summary statistics for the native population distribution (row 1), last sample (row 2) and the two sampling distributions, in this case mean and variance (rows 3 and 4).
- SOCR Home page: http://www.socr.ucla.edu
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