什么是名义组技术？

Candidate classification items were generated by expert opinion and were reviewed by a group of vasculitis experts across a range of specialties using a nominal group technique.

 候选分类项目由专家意见生成，并由一组不同专业的血管炎专家使用名义组技术进行评审。

什么是名义组技术。可以查到该技术的具体做法，但不知为什么叫名义组技术而不是其他名称。