Qualified Data are any numerical information that has been modified or adjusted by mathematical or statistical operations and which may be limited in use for a specific function.

Quality is the totality of features and characteristics of a product or service that bear on its ability to meet the stated or implied needs and expectations of the user, i.e., fitness for use.

- Quality assessment : A quality assessment is "The evaluation of Environmental data to determine if they meet the quality Criteria required for a specific application" (QAMS 1993, 17).

- Quality assurance : Quality assurance is a complete program designed to produce results which are valid, scientifically defensible, and of known precision, bias, and accuracy.

- Quality Assurance (QA) : A Quality Assurance (QA) is Quality Assurance is a way to see that QC is maintained and is we are monitoring the right things to detect changes in water quality.

The Quality Assurance Manager (or QA Officer or QA Coordinator is the individual designated within an organization having management oversight and responsibilities for planning, documenting, coordinating, and assessing the system effectiveness for ensuring the value of the work.

The Quality Assurance Project Plan (QAPP) is the document that describes the intended technical activities and project procedures that will be implemented to ensure that the results of the work to be performed will satisfy the stated performance or acceptance criteria.

A Quality control is the system of activities to ensure a quality product , including measurements made to ensure and Monitor data quality. Includes calibrations, duplicate, blank, and

- Quality Control: A Quality Control (QC) is the system of checks that are used to generate excellence, or quality, in a program (a monitoring program, for example). QC asks if we are doing things right

A Quality Control Sample is one of any number of test specimens, such as a Proficiency Test or blank, intended to demonstrate that a measurement system or activity is in check.