Experts hired to testify in court need to know how to make convincing presentations  Such experts are evaluated by juries in terms of their ability to present the steps by which they arrived at their conclusions clearly and confidently
As a result, some less expert authorities who are skilled at producing convincing testimony are asked to testify rather than highly knowledgeable but less persuasive experts
The opera singer with the best voice is the appropriate choice even for minor roles, despite the fact that an audience may be more affected by a singer with greater dramatic ability but a lesser voice.