Minitab's Power and Sample Size Tools
For any type of work, you need a specific tool that offers the right amount of power. You don’t use a sword to cut vegetables or a knife in a battle-field because neither provides you the desired outcome. Minitab, designed to meet specific needs for six sigma professionals, is statistical software that provides an effective and efficient way to input and control numerical data, recognize trends and patterns, and derive insights.
While performing the statistical test, you have to consider the precision and have to be confident with your results to meet your goals. Minitab’s Power and Sample Size tools enable users to balance these issues. It can efficiently determine exactly how much data is needed to be sure about the results of an analysis.
Understanding Power and Sample Size
Minitab’s Power and Sample Size tools collect enough data to conduct a thorough analysis. In order to be more precise, Minitab can assess the statistical power of tests that have already been run and estimate the sample size. Gathering fewer data restricts the reliability of an analysis, but gathering too much data leads to wastage of resources.
Statistical power refers to the probability that your hypothesis test identify a significant difference or effect when one truly exists. For example, testing DVD players requires a low degree of certainty as compared to testing critical airplane parts that demand a higher degree of certainty.
To differentiate between two papers, how many samples are needed if the average thickness of paper differs from one supplier to another? How many times should an experiment be replicated to have at least an 85% chance of detecting the factors that significantly affect a manufacturing process? The answers to these questions become easy with Minitab’s Power and Sample Size tools.
Minitab Statistical Software does following statistical tests:
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Sample Size for Estimation
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1-Sample Z
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1- and 2-Sample t
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Paired t
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1 and 2 Proportions
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1- and 2-Sample Poisson Rate
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1 and 2 Variances
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One-Way ANOVA
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2-Level Factorial Design
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Plackett-Burman Design
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General Full Factorial Design
The tool has the capability to examine how different test properties affect each other. The test includes boxplots, scatterplots, and histograms and has the ability to calculate descriptive statistics. It’s an essential tool any Six Sigma program making it an important tool in process improvement.
For example, while testing two samples, t-test can calculate:
- Sample sizes - the number of observations in each sample.
- Variances - the minimum variance between the two samples
- Power - the probability of detecting a significant difference when one truly exists.
Minitab has the ability to calculate the third property if the user enters values for any two. For instance if the values for the sample sizes and power are entered, Minitab determines the minimum variance between the two sample
Minitab Statistical Software is the most preferred data analysis tool for businesses of all sizes – small, medium, big. It is used by thousands of distinguished companies including RBS, Toshiba, Boeing and the leading
Six Sigma consultants. The Power and Sample Size tools in Minitab make it easier than ever to be sure you can count on the results of your analyzes.