This chapter is from the book
This chapter is from the book
This chapter is from the book
1.6 Sample Selection Methods
Sampling can be done either with or without replacement of the items being selected. Almost all survey sampling is done without replacement.
Sampling with Replacement
CONCEPT A sampling method in which each selected item is returned to the frame from which it was selected so that it has the same probability of being selected again.
EXAMPLE Selecting items from a fishbowl and returning each item to it after the selection is made.
Sampling Without Replacement
CONCEPT A sampling method in which each selected item is not returned to the frame from which it was selected. Using this technique, an item can be selected no more than one time.
EXAMPLES Selecting numbers in state lottery games, selecting cards from a deck of cards during games of chance such as blackjack or poker.
INTERPRETATION Sampling without replacement means that an item can be selected no more than one time. You should choose sampling without replacement instead of sampling with replacement because statisticians generally consider the former to produce more desirable samples.
spreadsheet solution
Entering Data
Enter the data values of a variable in a blank column of a worksheet. Use the row 1 cell for the variable name.
To create a new file (workbook) that contains a blank work-sheet for your entries, select File ® New and, in the New panel, double-click the Blank Workbook icon. (In Excel 2007, click the Office Button instead of selecting File.) To enter data into a specific cell, move the cell pointer to that cell by using the cursor keys, moving the mouse pointer, or completing the proper touch operation. As you type an entry, the entry appears in the formula bar area located over the top of the worksheet. You complete your entry by pressing Tab or Enter or by clicking the checkmark button in the formula bar.
To save your new file, select File ® Save As and, in the Save As dialog box, navigate to the folder where you want to save your file. Accept or revise the filename and then click Save. To later retrieve the file, select File ® Open and in the Open dialog box, navigate to the folder that contains the desired file, select the desired file from the list, and then click Open. (In Excel 2007, you begin these operations by clicking the Office Button, not by selecting File.)
Throughout this book, the symbol ® links a sequence of Ribbon or menu selections. File ® New means to first select the File tab and then select New from the list that appears.