Cross Table

The cross tabulation is a very basic and simple way of data analysis, Mani cross tables are oftem equivalent to a bar graph in 3 dimensions, which explains totals of co-ocurrences.

Example: Two batches (A and B) of manufactured items were randomly sampled to determine if the proportion of defective items is different fot the two batches. The data are described below.

^{click here to download the data}

To use the tool Cross Table the user must follow these steps:

1. Access the menu:

Action → Basic Statistics → Cross Table

2. The following window will appear;

3. In the field Data Set, we choose between Complete Data if we have all the data set or Summarized Data if we already have the corss table. In this case we have all the data set so, we will select Complete Data.

With the cursor in the field Factor Line select the column (or row) that contains its data (which you wish to insert in the cross table lines). Use the mouse to select, without however, select the name of the column (if it exists);

4. With the cursor in the field Factor column select the column (or row) that contains its data (which you wish to insert in the cross table columns). Use the mouse to select, without however, selecting the name of the column (if it exists);

5. In the board Show Results, choose one of the options. We suggest the option New Sheet, because Action does not have the undo command;

6. To finish, click Ok.

REMARK: Look at item 5 of the case ANOVA - Analysis with a single factor and various levels (page 5) and the remark after this item to more information about the completion of the field Factors.

Results and Interpretation

The released table shows the absolute and percentage events of studied cases. We see that 58.33% of the total of defective items (12 in general) are in the first batch (B), and the rest in batch A, 41.67%.  This difference does not seem significant, once both percentages are relatively close.