CVSEVALUATE command
Concept Information
For classical variables sampling, provides four different methods for projecting the results of sample analysis to the entire population.
Syntax
CVSEVALUATE BOOKED book_value_field AUDITED audit_value_field ETYPE {MPU|DIFFERENCE|RATIO SEPARATE|RATIO COMBINED|ALL} STRATA boundary_value <,...n> POPULATION stratum_count, stratum_book_value <,...n> CONFIDENCE confidence_level CUTOFF value, certainty_stratum_count, certainty_stratum_book_value ERRORLIMIT number PLIMIT {BOTH|UPPER|LOWER} <BCUTOFF value, certainty_stratum_count, certainty_stratum_book_value> <TO {SCREEN|filename}>
Parameters
Note
If you are using the output results of the CVSPREPARE and CVSSAMPLE commands as input for the CVSEVALUATE command, a number of the parameter values are already specified and stored in variables. For more information, see CVSPREPARE command and CVSSAMPLE command.
Do not include thousands separators, or percentage signs, when you specify values.
Name | Description |
---|---|
BOOKED book_value_field | The numeric book value field to use in the evaluation. |
AUDITED audit_value_field | The numeric audit value field to use in the evaluation. |
ETYPE MPU | DIFFERENCE | RATIO SEPARATE | RATIO COMBINED | ALL |
The estimation type to use:
For more information, see Which estimation type should I use? |
STRATA boundary_value <,...n> | The upper boundary values to use for stratifying the book_value_field. |
POPULATION stratum_count, stratum_value <,...n> | The number of records and the total value for each stratum in the book_value_field. |
CONFIDENCE confidence_level | The confidence level used during the preparation stage of the classical variables sample. |
CUTOFF value, certainty_stratum_count, certainty_stratum_book_value |
|
ERRORLIMIT number |
The minimum number of errors you expect in the sample. Note If the actual number of errors you found when you analyzed the sample is less than the ERRORLIMIT number, the only evaluation method available is mean-per-unit. |
PLIMIT BOTH | UPPER | LOWER |
The type of precision limit to use:
For more information, see CVSPREPARE command. |
BCUTOFF value, certainty_stratum_count, certainty_stratum_book_value optional |
|
TO SCREEN | filename |
The location to send the results of the command to:
|
Examples
Project errors found in the sampled data to the entire population
You have completed your testing of the sampled data and recorded the misstatements you found. You can now project the errors you found to the entire population.
The example below uses the Difference estimation type to project the results of sample analysis to the entire population:
CVSEVALUATE BOOKED invoice_amount AUDITED AUDIT_VALUE ETYPE DIFFERENCE STRATA 4376.88,9248.74,16904.52,23864.32 POPULATION 1279,3382131.93,898,5693215.11,763,9987014.57,627,12657163.59,479,13346354.63 CONFIDENCE 95.00 CUTOFF 35000.00,36,1334318.88 ERRORLIMIT 6 PLIMIT BOTH TO SCREEN
Remarks
For more information about how this command works, see Evaluating errors in a classical variables sample.
Which estimation type should I use?
The estimation type that you should use depends on the nature of the data: the sample book values, the sample audit values, and the relation between them.
Guidelines
The guidelines below help you select an estimation type.
Tip
If you want to compare the results produced by different estimation types, you can specify ETYPE ALL to include all estimation types in the evaluation output.
Estimation type | Presence of misstatements | Size of misstatements | Sign of book values | Comparison of strata ratios |
---|---|---|---|---|
Mean-per-unit |
No misstatements, or very few misstatements The only valid estimation type if there are no misstatements, or very few misstatements, in the audited sample population. |
n/a | n/a | n/a |
Difference |
Misstatements required Requires a number of misstatements in the audited sample population. For example, 5% or more of the samples contain misstatements. |
Misstatements are non-proportional More suitable when misstatements are non-proportional: the size of a misstatement is not related to the size of the associated book value. In other words, small and large book values can have either small or large misstatements. |
n/a | n/a |
Ratio Separate |
Misstatements are proportional More suitable when misstatements are proportional: the size of a misstatement is related to the size of the associated book value. In other words, small book values have small misstatements, and large book values have large misstatements. |
Book values have the same sign All sample book values must have the same sign: either all positive, or all negative. |
Ratios vary More suitable when the ratio of average sample audit value to average sample book value varies widely between strata. |
|
Ratio Combined |
Ratios are consistent More suitable when the ratio of average sample audit value to average sample book value is relatively consistent between strata. |