One of the most critical aspects of building trust in data quality is abiding by pre-defined ways of collecting and sharing data.
Certification/accreditation and associated definitions
- Best Practice: An agreed way of doing something.
- Standard method: An agreed method of doing something; bringing together expertise of wide range of users and end users to establish a best practice method/approach to doing something.
- Compliance: The act of following a method or process
- Quality Assurance: Assessing the whole method or process to prevent any errors or mistakes
- Quality Control: Assessing the possible errors and mistakes within a process or method.
- Accreditation/Certification: Official recognition of individuals’ or organisations’ compliance to a standard method. This can range from local certification following training e.g. ARMI to professional level accreditation process against a national/international standard (BSI, CEN, ISO) used by the Environment Agency and water company labs.
Quality Assurance (QA) versus Quality Control (QC)
Quality Assurance (QA)
Quality Assurance (QA) is a ‘proactive process’ that assesses the whole method or process to prevent any errors or mistakes.
- Focus is on the prevention of mistakes and errors
- Process-based approach
- Manages quality
Sampling example: a QA process would be calibrating your Hanna checker to test for phosphates using a sample blank to ‘zero’ your sample between each sample.
Data example: a QA process would only allow a volunteer to enter readings within the possible range. The user could not enter a pH above 14 or a phosphorus reading above the detection limit of their equipment.
Quality Control (QC)
Quality Control (QC) is a ‘reactive process’ that assesses the possible errors and mistakes within a process or method.
- Focus on the identification of mistakes and errors
- Product-based approach
- Verifies the quality
Sampling example: a QC process would be if you noticed a volunteer was always recording a zero value on their Kyoritsu tests for phosphate-phosphorus and so you meet with them to ensure they’re doing the test correctly. You then replace equipment as it appears sample tubes are out of date.
Data example: a QC process in water monitoring would be to have an expert review results to check for results that don’t make sense for a specific waterbody. They may catch an error, such as the reading for phosphorus being recorded where the pH would be recorded, or note that results are in the wrong units.