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14440CAUSEweb.orgen-useditor@causeweb.orgwebmaster@causeweb.orgWed, 23 Apr 2014 12:00:00 -0400Sat, 29 Jun 2013 12:00:00 -0400http://www.rssboard.org/rss-2-0-1The Student-t Test for Two Samples
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http://www.causeweb.org/cwis/index.php?P=FullRecord&ResourceId=1369This calculator computes summary statistics, the t-statistic, degrees of freedom (DF), and p-value for the Student t-Test. The user inputs values for two samples. The null hypothesis is that the populations have identical mean values.Sun, 24 Feb 2013 11:16:43 -0500IDEAL: Two-Sample Hypothesis Testing
http://www.causeweb.org/cwis/index.php?P=FullRecord&ResourceId=1312
http://www.causeweb.org/cwis/index.php?P=FullRecord&ResourceId=1312This example compares balance measurements in elderly people with those of young men through two-sample hypothesis testing for means. Two applets are provided; one for testing the assumptions beneath two-sample hypothesis tests, and one for calculating the test statistic and p-value.Sun, 24 Feb 2013 10:52:30 -0500IDEAL: Hypothesis Testing for Paired Differences in Means
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http://www.causeweb.org/cwis/index.php?P=FullRecord&ResourceId=1313This page provides three examples designed to illustrate hypothesis testing for paired differences in means. Example #2 requires Lisp-Stat. The other two examples each contain applets that calculate the test statistic and p-value. Examples #1 and #3 are about city murder rates and types of corn seed, respectively.Sun, 24 Feb 2013 10:49:49 -0500IDEAL: Hypothesis Testing
http://www.causeweb.org/cwis/index.php?P=FullRecord&ResourceId=1311
http://www.causeweb.org/cwis/index.php?P=FullRecord&ResourceId=1311This module introduces hypothesis testing with an example on breast cancer rates of Peurto Rican women. The applet provided allows users to manipulate power type, sigma, alpha, delta, and sample size. The Example link at the bottom of the page provides a more detailed discussion of power and instructions for the applet.Sun, 24 Feb 2013 10:18:17 -0500IDEAL: Confidence Intervals for Paired Differences
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http://www.causeweb.org/cwis/index.php?P=FullRecord&ResourceId=1310This page provides two examples that illustrate confidence intervals for paired differences in means. Each exercise provides an applet which graphs the data and calculates the interval. The first example is about city murder rates, and the second is about preparation of tobacco leaves.Sun, 24 Feb 2013 10:15:43 -0500IDEAL: Confidence Intervals
http://www.causeweb.org/cwis/index.php?P=FullRecord&ResourceId=1309
http://www.causeweb.org/cwis/index.php?P=FullRecord&ResourceId=1309This module contains an applet which illustrates factors affecting the width of confidence intervals for means. Users can manipulate the values of the population mean, population standard deviation, the sample size, and the level of confidence. Two follow-up examples, Cholesterol and Speed Of Light, further illustrate this concept.Sun, 24 Feb 2013 10:13:20 -0500Confronting Some Statistical Inference Misconceptions
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http://www.causeweb.org/cwis/index.php?P=FullRecord&ResourceId=1301This lesson poses a series of questions designed to challenge students' possible misconceptions of statistical inference and hypothesis testing. The lesson uses the statistical software, Fathom, and three datasets with information on the number of chips per canister distributed by a snack maker. The data can found at the relation address below.Sun, 24 Feb 2013 09:33:39 -0500A Useful Display of a Normal Population
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http://www.causeweb.org/cwis/index.php?P=FullRecord&ResourceId=1125This article describes how to make a physical model of the normal distribution and use it to illustrate the concepts of sampling distributions, confidence intervals, and hypothesis testing.Mon, 21 Jan 2013 06:42:08 -0500Independent Group t-Test
http://www.causeweb.org/cwis/index.php?P=FullRecord&ResourceId=1600
http://www.causeweb.org/cwis/index.php?P=FullRecord&ResourceId=1600This tutorial on the Two Sample t test includes its definition, assumptions, hypotheses, and results as well as tests for equal variance and graphical comparisons. An example using output from the WINKS software is given, but those without the software can still use the tutorial. An exercise is given at the end that can be done with any statistical software package.Wed, 27 Sep 2006 09:51:32 -0400Single Sample t-test
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http://www.causeweb.org/cwis/index.php?P=FullRecord&ResourceId=1599This tutorial on the One Sample t test includes its definition, assumptions, hypotheses, and results. An example using output from the WINKS software is given, but those without the software can still use the tutorial. An exercise is given at the end that can be done with any statistical software package.Wed, 27 Sep 2006 09:51:32 -0400Polls: What Do the Numbers Tell Us?
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http://www.causeweb.org/cwis/index.php?P=FullRecord&ResourceId=1554This tutorial opens with a survey on polling. Upon completing the survey, students are taken through an election example which uses polling to explain random sampling, bias, margin of error, and confidence intervals.Tue, 12 Sep 2006 11:51:51 -0400Confidence Limits
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http://www.causeweb.org/cwis/index.php?P=FullRecord&ResourceId=1564This lesson introduces confidence intervals and how to calculate them. A multiple choice test is given at the end. Thu, 31 Aug 2006 02:09:33 -0400Two Sample Tests
http://www.causeweb.org/cwis/index.php?P=FullRecord&ResourceId=1565
http://www.causeweb.org/cwis/index.php?P=FullRecord&ResourceId=1565This lesson introduces two sample hypothesis testing for means and discusses the one-tailed and two-tailed t-tests.Thu, 31 Aug 2006 02:09:33 -0400Student's t-Test for Independent Samples
http://www.causeweb.org/cwis/index.php?P=FullRecord&ResourceId=1520
http://www.causeweb.org/cwis/index.php?P=FullRecord&ResourceId=1520This tutorial explains the theory and use of Student's t-test and demonstrates it with an example on final exam scores. Data is given as well as SPSS and Minitab code.Tue, 29 Aug 2006 06:06:17 -0400Student's t-Test for Matched Pairs
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http://www.causeweb.org/cwis/index.php?P=FullRecord&ResourceId=1521This tutorial explains the theory and use of Student's t-test for matched pairs and demonstrates it with an example on project quality. Data is given as well as SPSS and Minitab code.Tue, 29 Aug 2006 06:06:17 -0400Summary Statistics Calculator
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http://www.causeweb.org/cwis/index.php?P=FullRecord&ResourceId=1501This applet allows users to enter two sets of data and retrieve summary statistics on each set as well as a comparison of the two sets. The calculator returns sample size, mean, standard deviation, standard error, and 95% confidence limits for the mean. Key Words: Descriptive Statistics; Confidence Interval.Wed, 23 Aug 2006 09:33:30 -0400Hypothesis Test Exercise
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http://www.causeweb.org/cwis/index.php?P=FullRecord&ResourceId=1451This exercise checks users hypothesis testing skills. Poems by the same author have on average 6.9 new words with a standard deviation of 2.7 words. A new group of poems has on average 8.2 new words. Were these new poems written by the same author? A calculator is provided which calculates probabilities and quantiles for the binomial, normal, Poisson, t, F, and Chi-square distributions.Tue, 1 Aug 2006 02:34:40 -0400Confidence Intervals
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http://www.causeweb.org/cwis/index.php?P=FullRecord&ResourceId=1456This applet introduces the concept of confidence intervals. Select an alpha level, sample size, and the number of experiments, and click "Play." For each sample, the applet will show the data points as blue dots and the confidence interval as a red, vertical line. The true population mean is shown as a horizontal purple line, and green ovals indicate which intervals do not contain the true mean.Tue, 1 Aug 2006 02:34:40 -0400Choosing the Right Test
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http://www.causeweb.org/cwis/index.php?P=FullRecord&ResourceId=1457This page helps readers know which statistcal tests are appropriate for the different types of data. Two charts display the information. A discussion of study design and sample size, as well as exercise questions with solutions are also provided.Tue, 1 Aug 2006 02:34:40 -0400Statistical Tools: One Arm Survival
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http://www.causeweb.org/cwis/index.php?P=FullRecord&ResourceId=1281This page calculates either estimates of accrual or power for null and alternative median survival rates assuming an exponential distribution. The program gives critical values for either median survival or survival probabilities. Fri, 2 Jun 2006 01:14:53 -0400Statistical Tools: Two Arm Normal
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http://www.causeweb.org/cwis/index.php?P=FullRecord&ResourceId=1287This page calculates either estimates of sample size or power for differences in means. The program allows for unequal sample size allocation between the two groups. Fri, 2 Jun 2006 01:14:53 -0400Statistical Tools: One Arm Nonparametric Survival
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http://www.causeweb.org/cwis/index.php?P=FullRecord&ResourceId=1285This page calculates either estimates of accrual or power for null and alternative survival functions based on the non-parametric estimate of the survival distribution. The program also gives large sample expected critical values for median survival or survival probabilities.Fri, 2 Jun 2006 01:14:53 -0400Statistical Tools: One Arm Normal
http://www.causeweb.org/cwis/index.php?P=FullRecord&ResourceId=1284
http://www.causeweb.org/cwis/index.php?P=FullRecord&ResourceId=1284This page calculates either sample size or power for a one sample normal problem. User inputs hypothesis test parameters. Fri, 2 Jun 2006 01:14:53 -0400The One-Sample t Test
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http://www.causeweb.org/cwis/index.php?P=FullRecord&ResourceId=208This section on Common Statistical Tests uses an example on faculty publications to show users how to perform a one-sample t test. The discussion includes one-tailed and two-tailed tests. Tue, 9 Aug 2005 01:21:59 -0400Comparing Two Groups
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http://www.causeweb.org/cwis/index.php?P=FullRecord&ResourceId=1606This page discusses the procedures and applications of the two sample t test and the paired t test.Tue, 9 Aug 2005 01:16:35 -0400