They are used to classifying from two points of view:
For its use
• Continuous use papers.
• Papers for temporary use.
By its use: The working papers can contain useful information for several years (articles of incorporation, contracts with terms greater than one year or indefinite, organization charts, account catalogs, procedure manuals, etc.).
Due to their more or less permanent utility, these types of papers are used to keeping in a special file, particularly when the auditor's services are required for several accounting years.
Due to its Content: Although in design and content the working papers are as varied as one's own imagination, in the aftermath of the audit work there are key roles whose content is more or less defined.
Importance
The results of selective tests must be carefully weighed in order to generalize them to the whole. Satisfactory results must give assurance while negative results can cause an extension of the work, which may be, expanding the sample or changing the focus, or they can simply be considered fully applicable to the universe, and consequently considered erroneous.
Classification
The parts that make up the whole to be tested are called UNIVERSE and the selected parts are called SAMPLE, the relationship between the sample and the universe depends on many factors, including internal control, the homogeneity of the items, and the characteristics of the universe to be examined.
In auditing, experience is essential to determine how many and which items should make up the sample, or otherwise, what should be the scope in the application of the procedures.