The first Random Sampling menu item - Prepare New Data and Sample - calls the following user dialog form.

The form has 7 text boxes for completion

• the sample size - a whole number greater than zero
  
• the general name of the test/data source - a concise description that is sufficiently unique to allow you to find the data and test sheets again
  
• the first data source name - each data source must have its own unique name
  
• the number of pages in the data source - a whole number greater than zero
  
• the number of transactions on the first page - a whole number greater than zero - you may have to count them
  
• the number of transactions per inner page - the default system assumption is that all inner pages have the same number of transactions
  
• the number of transactions on the last page (of this source) - this is frequently less than either the first page or an inner page - you may have to count them
  

Click 'Enter Details' to post the details from your first source. The following systems message will be generated.

Click 'Yes' to enter details of another source.

Note that

• the sample size and test name text boxes de-activated - you cannot change then from this point onwards - only the text boxes below the black dividing line can be editied
  
• because there is only one page in this source the 'inner page' and 'last page ' values are set to zero and cannot be edited
  

Click 'Enter Details' again to accept this information on the new source. The systems source message will generate until you click 'No' to it.

The next systems message is

The random sampling function recognises that the default assumption about all the inner pages having the same transaction numbers may be false. Clicking 'No' at this juncture allows the user to correct any errors in page values for inner pages before preparing a random sample based on the description. Other wise a random sample of the transactions in the populations is presented immediately.

The user should make corrections in column 'D' of the data sheet worksheet.

Remarks

As a general rule, the information about a population of transaction comes from a single source. There are however a significant number of exceptions to the general case.

For example, in accounting terms, one might have three populations

• accrued invoices from the last period
  
• standard invoices for this period
  
• prepaid invoices for next period
  

that for the purpose of your sample you wish to treat as one combined population.

This data preparation process is constructed around the likelihood that you will want to include several sources of data within the total population.

See also

Random Sampling