Server User Guides > Survey Tabulation > Working with hierarchical data > Setting the population level
 
Setting the population level
Understanding population levels shows the implication of populating tables at different levels when you are working with the hierarchical view. This topic explains more about the default population level and how to change the population level.
Setting the level
You set the population level for a table by selecting the required level from the Possible Levels list in the Select Level dialog. You open this dialog by clicking Edit Level on the Advanced view of the Define tab.
The list contains the names of the valid levels for your table and provides an option to select the default level. The name of the top level is always Top and the names of the lower levels are the same as the names of the corresponding loops.
Default level
This is the level at which a table is populated when you do not explicitly specify the population level. The default level depends on the level of any filters and of all of the variables that are in the table (including any numeric variables included in the cell contents):
If all of the filters and variables are at the same level, the default level is the level of the variables.
If all of the variables and filters are at levels that are direct descendants of each other, the default level is the level of the lowest-level variable or filter.
If some or all of the variables or filters are at parallel levels (levels that are not direct descendants of each other), the default level is the first common parent level. (For an example that illustrates this, see Tabulating variables from different “parallel” levels.)
The default level is slightly different when a grid or loop slice is being used. For more information, see Grid and loop slices.
Example
To illustrate this, create the first seven tables shown in Understanding population levels:
1 Start UNICOM Intelligence Reporter - Survey Tabulation using the Household sample data set. For more information, see Sample data.
2 On the Preferences tab, click the Modify button that is just above the list of cell contents.
3 In the Modify Cell Items dialog, remove the Column Percentages item, and then click OK.
4 From the menu at the top of the Preferences tab, and then click Set as Default.
5 On the Define tab, create table 1: Add the HouseType variable to the side axis and the Region variable to the Top axis.
6 Create table 2: Expand the Person loop, and then add the Occupation variable to the side axis and the Gender variable to the Top axis.
7 Create table 3: It is identical to table 2, but change the level to the household (Top) level: click Advanced View > Edit Level, and then select Top.
8 Create table 4: Expand the Trip loop (which is inside the Person loop), and then add the Country variable to the side axis and the Purpose variable to the Top axis.
9 Create table 5: It is identical to the table 4, but change the level to Person.
10 Create table 6: Expand the Person loop, and then add the Gender variable to the side axis. Expand the Trip loop, and then add the Purpose variable to the Top axis.
11 Create table 7: It is identical to the sixth table, but change the level to Person.
You set the population level for tables 3, 5, and 7. For all of the other tables, you used the default level:
Table 1 has two top-level variables only, so the default level is the top level.
Table 2 has two person-level variables only, so the default level is the person level.
Table 4 has two trip-level variables only, so the default level is the trip level.
Table 6 has one person-level variable and one trip-level variable. The trip level is a child of the person level, so the default level is the trip level.
You can use the Level field to show the population level in a header or footer. This is shown in the right header position by default. For more information, see Header and footer fields.
See also
Working with hierarchical data