Worksheet Remodeling, Part III
Manipulating Content
Welcome to the third and final installment of our Accessing the Power of Minitab mini-series on data manipulation tools. In the previous two installments (Losing the Clutter and Rearranging for Clarity), the tools we looked at clarified and added meaning simply by shuffling data around. But the Data menu contains a number of additional tools that work by changing the characteristics of the data itself.
In this short article, we'll cover some of them and show you how they can help you get the most out of your data.
Know your options
The rush to collect data can sometimes cause problems that aren't obvious until you begin your analysis. Maybe it's the abbreviated values used when recording data that only make sense to the person who collected it, or the hastily assembled worksheet that results in a numeric column being coded as text. Here are three data manipulation tools that can solve problems like these, and many more.
Change data type
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An error in entering this data left this column of numeric values incorrectly classified as text data. Until it's addressed, Minitab won't allow its use as numeric data. | With just a few clicks, Data > Change Data Type corrects the problem, and the data can now be used as intended. |
Code data
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When it was originally recorded, nondescript 0s and 1s denoted which fabric samples had been pretreated and which had not. | Using Data > Code, all of the 0s have been changed to "Pretreated" and 1s to "No Treatment." Now the graphs and analyses that reference these values will be more clearly descriptive. |
Extract from Date/Time
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You suspect that the day of the week plays an important role in the number of technical support calls you receive, but the date of each incident doesn't indicate it. | Using Data > Extract Date/Time, you can create a new column that "extracts" the day of the week from each date. Now you can use this column to test your suspicion. |
Try it yourself
Now that you've seen some of the helpful things they can do, let's see how easy these tools can be to use.
Suppose you've been given this worksheet of customer satisfaction data collected from five different franchises of a popular fast-food chain. You're interested in charting satisfaction ratings to see if they vary according to the day of the week. You want to recode the numeric ratings to more descriptive labels, and extract the day of the week from the date of each observation. |  |
First, extract the day from the date column. - Choose Data > Extract from Date/Time > To Text.
- In Extract from date/time column, enter Date.
- In Store text column in, enter Day.
- Check Day of week, and click OK.
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Now recode the ratings. - Choose Data > Code > Numeric to Text
- In both Code data from columns and Into columns, type Rating.
- In the first cell under Original values, type 1.
- In the first cell under New, type Poor.
- Now repeat the previous two steps to recode the original values 2, 3, and 4 to Fair, Good, and Excellent, respectively. Click OK.
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Now the data is ready for analysis. You'll be able to analyze and subset the data by day of the week, and graphs and output will use the more descriptive text labels (Poor, Fair, Good, and Excellent) that now make up the Rating column. |  |
Putting It to Use
In examples above, you can see that these tools aren't just used for correcting data-entry errors – they can help make good data sets more versatile and more descriptive. And while this installment ends our mini-series on data manipulation, it's really just the beginning in terms of the flexibility afforded by the tools in Minitab. With the rich collection of Minitab data manipulation tools at your disposal, you can quickly remedy any of the less than perfect data sets that you may encounter, making every Minitab session easier and more productive.