http://www.merlot.org:80/merlot/ A search of MERLOT materials Copyright 1997-2013 MERLOT. All rights reserved. Sun, 19 May 2013 22:30:57 PDT Sun, 19 May 2013 22:30:57 PDT http://www.merlot.org:80/merlot/images/merlot.gif http://www.merlot.org:80/merlot/ 44 34 http://www.merlot.org/merlot/viewMaterial.htm?id=82347 This tutorial will help you determine how accurate a sample mean is likely to be, and how this accuracy is related to the sample size. Brief reviews of the normal distribution and the Central Limit Theorem are included as supplemental materials. http://www.merlot.org/merlot/viewMaterial.htm?id=82334 This exercise will help the user understand the logic and procedures of hypothesis testing. To make best use of this exercise, the user should know how to use a z table to find probabilities on a normal distribution, and how to calculate the standard error of a mean. Relevant review materials are available from the links provided. The user will need a copy of the hypothesis testing exercise (link is provided), a table for the standardized normal distribution (z), and a calculator. The user will be asked several questions and will be given feedback regarding their answers. Detailed solutions are provided, but users should try to answer the questions on their own before consulting the detailed solutions. The end of the tutorial contains some "thought" questions. http://www.merlot.org/merlot/viewMaterial.htm?id=82345 This tutorial illustrates the relationship between statistical power and four features of the test situation. An applet allows the user to manipulate a factor and immediately see the effects on other factors. http://www.merlot.org/merlot/viewMaterial.htm?id=641891 The interactive WISE Confidence Interval Creation Applet allows instructors to demonstrate how sample size, alpha level, population shape, and variance affect confidence intervals. The user can generate a population distribution of interest or select a distribution from a menu, select a sample size and an alpha level.A press of the 'Sample' button displays a simulated sample and confidence interval for the population mean. The sample mean, standard deviation, and confidence interval are displayed, along with the option to display calculations for the confidence interval limits. Subsequent presses of the 'Sample' button produce new random samples with their associated confidence intervals. Up to 20 confidence intervals are displayed at one time, showing how confidence intervals differ by chance.This applet provides graphic evidence for why it is wrong to say that the population mean falls within a given confidence interval 95% of the time. Rather, 95% of confidence intervals are expected to contain the population mean IF assumptions are met. Manipulations of the population shape and the sample size easily produce situations where the assumption of normality is violated to an extent where standard procedures for constructing confidence intervals are clearly wrong. Students and instructors can have fun playing with the applet and interpreting findings.The applet is linked to a demonstration guide. http://www.merlot.org/merlot/viewMaterial.htm?id=82349 This tutorial takes the learner step-by-step in applying descriptive and inferential statistics using a real world situation. http://www.merlot.org/merlot/viewMaterial.htm?id=84498 Every day we have to make decisions about uncertain events like, 'Is that my phone ringing or one on the television?', or, 'Is the person talking to me telling the truth?' In this tutorial, you will learn about the Signal Detection Theory (SDT) model of how people make decisions about uncertain events. This tutorial explains the theory behind signal detection, covers several SDT measures of performance, and introduces Receiver-Operating Characteristics (ROCs). The tutorial is at an introductory level, but also has optional sections appropriate for more advanced students and researchers. The tutorial consists of explanatory text, interactive examples, and a question section suitable for a classroom assignment. The tutorial also contains a Java applet for computing and graphically portraying SDT models. This tutorial is introductory in level and builds upon other tutorials on the WISE Project's web site. The hypothesis testing tutorial is particularly appropriate, and it is also helpful to be comfortable working with z-scores. http://www.merlot.org/merlot/viewMaterial.htm?id=710136 The WISE Bootstrapping Applet can be used to demonstrate bootstrapping by creating a confidence interval for a population mean or median. The user can manipulate the population distribution, sample size, and number of resamples. An associated guide gives suggestions for teaching bootstrapping. http://www.merlot.org/merlot/viewMaterial.htm?id=82336 This applet serves to introduce the logic of hypothesis testing using z-scores. http://www.merlot.org/merlot/viewMaterial.htm?id=82338 This applet teaches fundamental properties of sampling distributions of means such as accuracy of sample means, probability, and effects of sample size. The applet does not allow the user to enter in specific data http://www.merlot.org/merlot/viewMaterial.htm?id=82351 This tutorial illustrates the basic principles of the Central Limit Theorem and enhances conceptual understand of why the Central Limit Theorem is important to inferential statistics.