What different sources are needed to verify authenticity for CMMI implementation? Ans. There are three different sources from which an appraiser can verify that an organization followed the process or not. Instruments: An instrument is a survey or questionnaire provided to the organization, project, or individuals before starting the assessment so that beforehand the appraiser knows some basic details of the project. Interview: An interview is a formal meeting between one or more members of the organization in which they are asked some questions and the appraiser makes some judgments based on those interviews. During the interview the member represents some process area or role which he performs. For instance, the appraiser may interview a tester or programmer asking him indirectly what metrics he has submitted to his project manager. By this the appraiser gets a fair idea of CMMI implementation in that organization. Documents: A document is a written work or product which serves as evidence that a process is followed. It can be hard copy, Word document, email, or any type of written official proof. The following figure is the pictorial view of the sources used to verify how compliant the organization is with CMMI.