In Ohio, an expert's opinion cannot be based on which of the following?

The correct choice, indicating that an expert's opinion cannot be based on facts or data not admitted into evidence, aligns with the fundamental principles of expert testimony under the rules of evidence. In legal contexts, expert witnesses are permitted to provide opinions based on reliable information, but that information must typically be rooted in data that has been presented and accepted during the proceedings.

This requirement ensures that the opinions offered by experts are grounded in evidence that has been scrutinized and subjected to the standards of admissibility, providing a basis for their credibility. Allowing opinions to be based on unadmitted facts or data could lead to the introduction of unreliable or irrelevant information, which would undermine the integrity of the court's deliberations and decision-making process. Therefore, maintaining this standard is essential for the fair administration of justice.

The other options involve sources of information that are generally acceptable for expert opinions, as they can contribute context and support for the expert's analysis. Expert literature, personal experiences, and expert interviews can all serve as valid foundations for expert opinions, provided that they are reliably linked to the subject matter at hand and comply with the rules governing admissibility in court.