Certification schemes are normally established to indicate that a product meets one or more sets of acceptable or minimum requirements. But what is acceptable? What may be acceptable to one buyer may not be acceptable to another. Certification programs may choose standards that result in certified products that satisfy a particular group or organization, such as the government, or the program may choose standards expected to satisfy a larger group of buyers or users. The choice of standards, therefore, may depend on the needs of the parties likely to use the certification.

Standards containing only one set of requirements and which define only one level of safety or quality are known as "pass- fail" standards. Either the product meets the minimum requirements (it passes and is certified) or it does not (it fails). Little or no attempt is made to convey information about the relative safety or quality of one certified product compared to other certified products (such as is conveyed through a grading system). Unless other methods are used to convey such information to buyers/users, a supplier may be less motivated to produce or supply products, which exceed the minimum requirements specified in the standard.

Certifiers may therefore wish to provide information on the quality or safety of one certified product relative to other certified products. This may be accomplished by selecting standards, which define several levels of safety or quality and by including a grading scheme in the certification program. Information can be conveyed by stating the expected life of the product, such as the expected number of miles that tires are supposed to travel, or the versatility of the product, such as portable fire extinguishers rated for several specified types of fires, or the efficiency of the product, such as the energy efficiency rating for appliances. Buyers, assured of at least a minimum level of safety and/or quality, can then choose among certified products based on any additional level of quality or safety that they desire, other characteristics or features, and/or price. A choice must also be made as to whether the establishment of conformity should be based on an assessment of a product's performance or its design. As noted above, performance standards, tend to be difficult to develop and difficult to use in assessing compliance. Problems may also arise in establishing reliable test methods for assessing conformity, thus potentially increasing certification costs.

The choice of standards for a certification program has a significant impact on the validity of the program, the value of the information conveyed by the certification, and the program's cost.