Introduction to MINITAB in the Saint Mary's Microcomputer Lab

II. Entering and correcting data


All your data must be entered into a Minitab Worksheet before any work can be done. If the data are already available in a Minitab worksheet, you will want to retrieve that worksheet. Otherwise, you will need to enter them by hand. [Minitab can read properly set-up text files, but use of such files will not be discussed here].

If the data have already been entered and saved in a Minitab worksheet you retrieve the worksheet using the File>Open Worksheet command - be sure to save any changes to the current data window first (unless you don't want them). See III.Saving your own data and retrieveing worksheets for more details.

To enter data by hand, you type it into the Data window, with one column for each variable, one value in each cell. Name the columns to match the names of the variables (see below).

To make the "Data" window active, click once on any part of the Data window that is visible (or Select Window>Data ). You select a cell as you would in a spreadsheet - by moving to it with the cursor keys or using the scroll bars and clicking on the desired cell .

Entering data: Type in the data, one entry to each cell, starting at the first numbered row of the column,. After the entry is typed, move to the next cell with the down arrow. The extra (not numbered - and shaded gray) row below the labels C1, C2, is for naming the column so you can remember what variable it represents. You must "accept" the last value entered before you can execute any commands - press the enter (return) key or any cursor key.

Changing values: If you mistype a value and notice it before you move off the cell, just use the backspace (or delete) key to erase it and retype it. If you notice a mistyped value later, select the cell and simply type the correct value - it will replace the earlier value.

Removing values: If you need to delete a value from the data (copied a number twice, etc.) you cannot use the delete or backspace key. (That will mark the cell as containing a "missing" value and will cause complications later). Instead, select the cell and select the Edit>Delete Cells command. You can remove a whole row by clicking on the row number (at the left of the Data window) and selecting Edit>Delete Cells.

Adding values that were left out: You can add values to a column simply by typing them at the end of the column. If the added values must be in a certain place in the column (if the order matters), you make a place for the value by selecting the cell which will follow the new value and then selecting Edit>Insert Cells. If you need to enter a row of values (one for each of the variables you have) you use Editor>Insert Row[The Editor menu is not the same as the Edit Menu] The new row will be inserted above the row containing the cursor.

Naming columns: In the cell at the top of the column (above the numbered rows - shaded) enter the name of the variable - height, or price, or whatever. This name will appear with the column number in all selection lists and will be used in showing results, so that you don't have to try to remember which numbers are in C1 & which are in C2 C2 is width. Names must be no more than 8 characters (letters and numbers) long and must begin with a letter.

Deleting columns: If you do not want a particular variable kept in the worksheet, use the Manip>Erase variables command and select the column(s) to be deleted.

As soon as you have the data entered correctly, you should save the Data window as a worksheet (File>Save Worksheet As.. command - see III. Saving and retrieving data for details) - be sure you save in your own filespace (on Diamond) or on your own floppy disk.


Last updated 8/10/00

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