A1is the qualification required by candidates who want to be involved in the assessment of NVQs or SVQs. The qualification covers the following aspects of assessment:

• Development plans for assessing competence with candidates
• Judge evidence against criteria to make assessment decision
• Provide feedback and support to candidates on assessment decisions
• Contribute to the internal quality-assurance process

 A2 is the qualification required if a candidate is to be involved in supporting evidence gathering and assessments by means of questioning and observation. The qualification covers the following aspects of assessment:

• Agree and review plans for assessing candidates' performance
• Assess candidates' performance against the agreed standards
• Assess candidates' knowledge against the agreed standards
• Make an assessment decision and provide feedback

 V1 is the qualification you will require if you are to be involved in the Internal Verification of NVQs or SVQs. The qualification covers the following aspects of verification:

• Carry out and evaluate internal assessment and quality-assurance systems
• Support assessors
• Monitor the quality of assessors' performance
• Meet external quality assurance requirements

Assesor Upskilling overview pdf is available here.
OCR A1 Unit ODF available here.