In an analysis, the base of a result is the records included in the universe being apportioned. For example, for the result "50% of all respondents are male", the base is all respondents. For "50% of females are under 30", the base is females.
The base is used when calculating percentages, and if values are being reported, it is also used to calculate the average.
Infotools Harmoni has a lot of flexibility to define the base for a result. The default is to use the Total. However, if the Total is not what you want, different bases can be applied either by using apply base Learn more about how to apply a base in the project tree. in the project design or by setting the percentage base in the analysis. Learn more about analysis drop zones.
Even with using the Total as the base, Infotools Harmoni offers flexibility for defining the Total using the Total options. Learn more about Total Options.
In this article
In most instances, the base used for calculations is the same as the Total option selected Learn more about Total Options.
- Information on the base used is available at the top of the analysis.
- The base identifies the value used as the denominator of percentage calculations.
- The base identifies the value used as the count for average calculations.
- The number the count is divided by, when calculating a percentage. To see the base of each cell in the analysis select B from the modify menu.
- The available base options vary depending on the content of the analysis.
In most instances, the base used for calculations is the same as the Total option selected.
1. Single axis analysis with Total Base
When analyzing a single standard axis that has no other bases specifically applied, the percentages and average calculations are based on the Total option Learn more about Total Options. selected.
Scenario |
total |
base |
Percentages Calculation |
What does this mean? |
Single Axis |
Total=2,771 | 2,771* The base is the same as the total. | Gender percentages based on Total |
45% of all respondents across all sources (Total) are males. Top 2 = 1,245/2,771 = 46% |
2. Cross tab analysis with Total Base
In an analysis with at least one variable down and one across, the default percentage base for calculations is the down dimension.
You can change to across percentages by dragging the across axis in the table heading into the percentage base zone.
Percentages can be interpreted as:
x% of those in the base item are the intersection item.
Down Percentages
Down Percentages calculate the percentage that each cell represents as a proportion of the total for each column in the table. The base for down percentages is the value in the Total row at the top of the table.
X% of those in the base item are down dimension item.
- Base definition: Overall Satisfaction percentages based on Gender
- 38% of Females are Top 2 in Overall Satisfaction.
Across Percentages
Across Percentages calculate the percentages that each item represents as a proportion of the total for each row in the table. The base for across percentages is the value in the Total column to the left of the table.
X% of those in the base item are across dimension item.
- Base definition: Gender percentages based on Overall Satisfaction
- 62% of those in the Top 2 of Overall Satisfaction are Female.
To change to across percentages drag the across axis in the table heading into the percentage base zone.
Scenario |
total |
base |
Percentages Calculation |
What does this mean? |
Down Percentages |
Total (qualified) Female=493 | 493* The base is the same as the total. | Overall Satisfaction percentages based on Gender |
38% of Females who gave a response are in the Top 2 of Overall Satisfaction. Top 2 = 187/493 = 38% |
Across Percentages |
Total (qualified) Top 2 = 300 | 300* The base is the same as the total. | Gender percentages based on Overall Satisfaction |
62% of those in the Top 2 of Overall Satisfaction are Females. Top 2 = 187/300 = 62% |
3. Analysis with a filter and Total Base
When you want to focus on a specific group within your sample, apply a filter using the analysis drop zones. Learn more about analysis drop zones.
- The filter selected applies to the entire analysis, i.e. the Total counts (numerator) and the base (denominator).
- Information on the filter being applied is displayed at the top of the analysis.
X% of those in the base item and filter item are down dimension item.
- Base definition: Overall Satisfaction percentages based on Gender
- 34% of female independent travelers are in the Top 2 of Overall Satisfaction.
Scenario |
total |
base |
Percentages Calculation |
What does this mean? |
Down Percentages with a filter (Traveler Type: Independent Traveler) |
Total (qualified) Female=291 | 291* The base is the same as the total. | Overall Satisfaction percentages based on Gender |
34% of female independent travelers who gave a response are in the Top 2 of Overall Satisfaction. Top 2 = 100/291 = 34% |
4. Base Options
Typically, the bases applied in an analysis relate back to the values in the Total of the row or column. However, should you wish to create an analysis where every cell in the table uses the value in the top left Total, i.e. the intersection of the Total row and Total column you can do so by using the base options available in the modify menu - (weighted base B ).
Cell Base
- This is the default selection, as typically the desire is for bases in the analysis to be cell-based.
- Each column has a different base for column-based percentages.
- Each row has a different base for row-based percentages.
X% of those in the base item are down dimension item.
- Base definition: Overall Satisfaction percentages based on Gender
- 38% of Females are in the Top 2 of Overall Satisfaction.
Total Base
- Percentages and/or averages are calculated by dividing the counts for an individual cell by the table total (usually on the top left cell of the table).
- All the cells in the table get the same base.
- Each percent shows the proportion of those in each row from among all those in the table.
X% of those in the selected total base item are down dimension item.
- Base definition: Overall Satisfaction percentages based on Gender Total (qualified)
- 22% of those in the Total (qualified) are Female and in the Top 2 of Overall Satisfaction
Scenario |
total |
base |
Percentages Calculation |
What does this mean? |
Cell Base |
Total (qualified) Female=493 | 493* The base is the same as the total. | Overall Satisfaction percentages based on Gender |
38% of Females who gave a response are in the Top 2 of Overall Satisfaction. Top 2 = 187/493 = 38% |
Total Base |
Total (qualified) Female=493 | 840* The base is using the table qualified total. | Overall Satisfaction percentages based on Gender Total (qualified) |
22% of those in the Total (qualified) are Female and in the Top 2 of Overall Satisfaction. Top 2 = 187/840 = 22% |
Total Base (Totals Only)
This option allows for the Total row to have a different directional base to the rest of the table. A common use of this would be when showing in the down table percentages and wanting to retain across percentages in the total row.
- Total row percentages are calculated across. It calculates the percentages that each item represents as a proportion of the total row in the table.
- This option is only enabled when Cell Base is used.
Where to from here?
Learn more about Bases:
Comments
0 comments
Please sign in to leave a comment.