Table Statistics

 

A table statistic automatically generates a row for the chosen statistic, using the table's rows as the basis for the computation. Table statistics are calculated based on one value for each row. If row values are ranges, you must use row statistics (see Row Options).

In Setup|Tables, select Statistics:

 

Sample size for statistic base

Displays the base for statistics, which is the total sample minus any ‘no answers’ and any rows specifically excluded from the statistic base.

 

Mean

Mean confidence interval - lower

Displays the lower mean confidence interval based on the selected confidence interval level specified using the Select Level option. The confidence interval level specified is used for calculating both the lower and upper mean confidence interval.

 

Mean confidence interval - upper

Displays the upper mean confidence interval based on the selected confidence interval level specified using the Select Level option. The confidence interval level specified is used for calculating both the lower and upper mean confidence interval.

 

Standard deviation

Measures variance from the mean for a set of values.

 

Standard error

Measures the standard error of means. It is calculated by dividing the standard deviation by the square root of the sample size.

 

Median

Reports the middle value of all values; half the values of the variable fall below the median and half fall above. For tables with ranges of values, use a grouped median.

 

Note: The Median does interpolate if the value falls at exactly 50%. The Grouped median does interpolate if you are using ranges.

 

Changing values for statistics

 

Grouped median

When row values are defined with ranges, you can specify a grouped median. If the values are not in a range and you want to do a group median, you can edit the row logic and use the at symbol (@) to change a single value to a range.

 

The @ symbol is used only for grouped medians. The grouped median is used on tables that have a range of values represented by a single value.

 

The regular median is used on tables where the median can be calculated on the actual values. The regular median might be used, for example, on a table that represents a question in which a respondent was asked to state his or her age in years. The @ is not used for the regular median. When a regular median is calculated, it uses the value in parentheses (or the # sign, described above, can be used to specify a different value for the calculation).

 

The grouped median is used on tables, for example, where a respondent is asked the range in which his or her age falls. Another example of a question type that would call for a grouped median in a table is income, where respondents are asked to indicate an income range, rather than a precise dollar value.

 

To calculate the grouped median, you need to specify mutually exclusive ranges with the @ sign. For example, for the following five age categories, we could use ranges in place of the original category values (1-5):

 

UNDER 25

1/79 (1)

@15-24.9

25-34

1/79 (2)

@25-34.9

35-44

1/79 (3)

@35-44.9

45-54

1/79 (4)

@45-54.9

55+

1/79 (5)

@55-64.9

 

 

For example, UNDER 25 would use the range 15-24.9 rather than the original value of 1; 25-34 would use the range 25-34.9 rather than the original value of 2 and so on.

 

To calculate both the grouped median and use a different value for the mean (described above), we could specify:

 

UNDER 25

1/79 (1)

#17.5 @15-24.9

25-34

1/79 (2)

#29.5 @25-34.9

35-44

1/79 (3)

#39.5 @35-44.9

45-54

1/79 (4)

#49.5 @45-54.9

55+

1/79 (5)

#59.5 @55-64.9

 

1st Quartile

Represents the value where 25% of the values fall below that value and 75% of the values fall above it.

 

3rd Quartile

Represents the value where 25% of the values fall above that value and 75% of the values fall below it.

 

Mode

Reports the value that occurs the most often.

 

Minimum

Shows the minimum value.

 

Maximum

Shows the maximum value.

 

Note: The Minimum and Maximum options are most meaningful when specified on a table defined using a Frequency Row(s).

 

Effective sample size for statistic base

Creates a row on your table displaying the effective sample size used when calculating T-scores for significance testing on means.

 

Mean number of mentions

Creates a row on your table displaying the total number of responses divided by the total number of respondents.

 

Percentiles

Show dollar sign ($)

For tables with dollar variables, displays dollar signs.

 

Show comma (,)

For tables, displays commas.

 

Scaling

When values are too large to fit in a cell, you can choose to scale all statistics.

Statistical testing

Statistical testing must be selected for a banner AND selected for a table.

 

To select statistical testing for a banner, use Setup|Banners. To select statistical testing for a table, use any of the following:

Decimal places

Select rows, if any to exclude from statistics

Every row in a table is included in the statistic base (except rows indicated as net rows by NET or as subtotal rows by SUB). Select rows you want to exclude (they are then highlighted).

 

Note: The Select rows, if any to exclude from statistics option is not available when using Setup|Globally Modify Tables|Table Statistics.

Related topics:

Setup|Job Settings|Statistics

Setup|Job Settings|Statistics Rows