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This course is part of our Lean Six Sigma Green Belt program, which consists of four courses designed to prepare you for the International Association of Six Sigma Certification (IASSC) Green Belt exam. We recommend you take all four courses in the program to be fully prepared for the exam.
Hypothesis testing allows you to make decisions about problems based upon statistically significant data. Depending on the nature of the hypothesis and data available, different tests should be applied.
In this course, you will learn about 20 different statistical tests. You will understand when to use each test, and when not to use them. You will also identify the level of risk associated with different statistics, and how best to work with them.
The training features plenty of opportunities to practice with examples, exercises and quizzes to test your knowledge. By the end of the course, you will have learned how to apply these hypothesis tests in your business processes.
The course is designed from the standpoint of making sound business decisions, not deriving proofs behind the formulas or statistics. You won't need to do any advanced math, as popular programs like Excel and Minitab will do that for you. While the computer crunches the numbers, you will learn how to read and interpret the test results to understand the messages in your data.
- 22 practical tutorials with videos, reference guides, exercises and quizzes.
- Designed to prepare you in part for the IASSC Green Belt exam. To prepare in full, you should also take the Lean Six Sigma Principles, Statistical Process Control, and Measurement Systems Analysis courses part of our four course Lean Six Sigma Green Belt program.
- Understand the concepts of hypotheses in problem solving.
- Identify the hypothesis testing process, and best practices that should be applied.
- Learn key decision factors for selecting which hypothesis test to use.
- Apply statistical analysis principles such as inferential statistics.
- Learn how to read residual graphs and conduct regression analysis.
- Conduct statistical hypothesis tests including T Tests, F Tests, ANOVA, and more.
- Aligned to the IASSC Lean Six Sigma Green Belt Body of Knowledge.
- The only method to earn an IASSC certification is to successfully sit for and pass an official IASSC certification™ exam, which can be taken through IASSC. We do not provide access to IASSC Certification exams.
Once enrolled, our friendly support team and tutors are here to help with any course related inquiries.
Estimated study time
11h for all materials
Creating an Hypothesis
Concept of Hypothesis TestingThe scientific method of analysis is to create an hypothesis, develop experiments that generate applicable data, then analyze that data to prove or disprove the hypothesis. This approach allows us to confidently answer inquiry questions with data. This lesson explains the concepts of hypotheses in problem solving.
Hypothesis Test Process
Effective hypothesis testing is a disciplined process. From writing the process, to designing the study or experiments, and finally analyzing the data, there are proven best practices that should be applied. This lesson presents and explains the hypothesis testing process as used in Lean Six Sigma.
A well written hypothesis contains two elements, the Null hypothesis and the Alternate hypothesis. Writing a clear hypothesis that can be quickly analyzed with a statistical test is a skill that will be illustrated and practiced in this lesson.
Hypothesis TestsThere are many different statistical tests that can be used with data to analyze an hypothesis. Which test depends upon the nature of the hypothesis and the test data. This lesson provides a roadmap for selecting an appropriate hypothesis test. The key decision factors for making the hypothesis test selection are addressed and illustrated.
Statistical Analysis Principles for Hypothesis Testing
Inferential StatisticsHypothesis testing relies on the principle of inferential statistics. A sample of a data set is statistically analyzed and the results area used to infer information about the entire data set. This lesson will discuss the application of this principle to Lean Six Sigma projects and provide groundrules for data sampling.
Confidence IntervalsIt is often impossible to analyze all the items in a data set, so a sample is used. But that means that the sample statistics might not perfectly represent the full data set. Depending upon the nature of the data and the sample, a confidence interval can be established around any sample statistic to show the range in which the actual statistic occurs. This lesson discusses how to calculate this range and criteria for sampling that impact this range.
Alpha and Beta RiskThe statistic created in an hypothesis test is only 100% valid for the sample used to conduct the test. The application to the broader data set includes some uncertainty about the statistic in the entire data set. Therefore, it is possible to reach a wrong conclusion about the entire data set based upon the analysis of the sample. The elements of that risk are classified as Alpha risk and Beta risk. This lesson explains these risks and their significance.
The P ValueInferential statistics relies on a statistical measure of goodness known as the "P" Value to determine whether to accept or reject the Null hypothesis. This P value is based upon the type of test conducted and the confidence interval and Alpha risk that are applied to the situation. This lesson explains the principle of the "P" value and its use in Lean Six Sigma projects.
Normal Versus Non-Normal
One of the most important criteria for selecting an hypothesis test is based upon whether the data is normal or non-normal. The normality question does not prove or disprove the hypothesis, rather it steers the nature of the analysis. This lesson reviews this concept and its application in hypothesis testing.
CorrelationA common investigation in Lean Six Sigma problem solving is to determine if two factors are correlated. This insight will often point to an underlying cause of the problem. This lesson explains how to do correlation analysis using both Excel and Minitab. It also includes a discussion of the Pearson correlation coefficient.
Simple Linear Regression
Simple linear regression analysis creates an equation that correlates two factors. This equation both assists in understanding problems, and it can also be used to manage the problem or process going forward. This lesson shows how to calculate this line with the help of either Excel or Minitab.
A statistical analysis or test creates a mathematical model to fit the data in the sample. The real world data seldom precisely fits the model. The differences between the model and the actual data is known as residuals. The residuals in any analysis, whether a regression analysis or another statistical analysis, will indicate how well the statistical model fits the data. When the residuals indicate a bad fit, a different analytical approach should be selected. This lesson explains how to read residual graphs and analysis.
Multiple Linear RegressionMany times there are multiple factors that are influencing the response variable in a problem. Multiple regression determines the relationship between the factors and the response, including interaction effects between factors. Like with simple linear regression, a formula is created that allows both analysis and prediction of the process and problem.
Non-Linear RegressionMany problems encountered in Lean Six Sigma projects are not a straight-line correlation effect like those discussed in simple linear regression or multiple regression analysis. The relationship is better modeled by an exponential curve or a parabola. These are referred to as nonlinear relationships. Minitab can help to determine the best fit curve and factors. In addition, the Box Cox Transformation can be used to assist in modeling these effects within the statistical analysis. This lesson discusses these topics and illustrates how to conduct this analysis.
Applying Statistical Hypothesis Tests
Test of Proportions
The One-Sample and Two-Sample Test of Proportions are used with discrete data. These tests determine whether the percentage of a particular attribute being studied is similar to or different from the selected target value. These tests are illustrated using both Excel and Minitab.
Chi Square TestWhen the data is discrete data, but there are more than two samples to be compared, the Chi Square test is used. This test is quickly accomplished using Minitab. It can be done using Excel, but requires several intermediate steps. This lesson explains this test approach.
Variance TestsMany of the hypothesis test approaches will change depending upon whether the continuous data has equal variances or unequal variances between data sets. Therefore, the F Test or Bartlett's Test must be completed to determine if variances are equal. The F test can be done with either Excel or Minitab. The Bartlett's Test can only be done using Minitab. This lesson explains these tests and how to read the statistic.
One of the most commonly used tests in Lean Six Sigma analysis is the T Test. This lesson discusses the One-Sample T Test, Two-Sample T Test, and the Paired T Test. Each of these can be easily accomplished using both Excel and Minitab.