Final answer:
A direct witness provides testimony based on personal experience, whereas an expert witness offers specialized knowledge to support their opinion. The assessment of an expert witness's testimony involves examining expertise consensus, possible biases, and the expert's background.
Step-by-step explanation:
The main point of difference between a direct witness and an expert witness lies in the type of testimony they provide in a legal setting. A direct witness, also known as a lay witness, provides testimony based on their personal observations or experiences of the facts of the case. They speak to what they saw, heard, or directly experienced. In contrast, an expert witness provides testimony based on their specialized knowledge, education, or experience in a particular field relevant to the case. They offer their opinion based on their expertise, which can help the court understand complex information or draw conclusions from the evidence.
Expert witnesses are expected to have a pre-analytical sense of their subject matter, which helps them avoid mistakes and provide a more detailed analysis. Ideally, an expert's testimony should align with the consensus among other experts in the field, and they should not be biased; factors such as history of biases, past record, and motives must be assessed when evaluating expert testimony. On the other hand, direct witnesses are evaluated based on their ability to be honest, unbiased, rational, and clearheaded regarding what they personally encountered.