Online health [mis]information processing and evaluation among older adults: Comparing individuals with varied abilities in information discernment

•We examined older adults’ information processing.•We categorized older adults into veracity detective vs. misjudgment wanderer.•Veracity detectives tended to use evidence derived from message arguments.•Misjudgment wanderers mostly relied on surface cues to evaluate information.•Detectives were more open-minded; wanderers were vulnerable to logical fallacy. Older adults are vulnerable to online health misinformation. This study fills a research gap by exposing older adults to a mixture of health-related misinformation and factual information and employing the think-aloud protocol in a semi-structured interview to understand information processing and evaluation in the moment of information engagement. The participants were categorized into two groups based on their abilities to discern misinformation. Via thematic analysis, we compared the two groups and found distinctive information processing patterns between them. We propose guidelines for evaluating online misinformation based on the best practices of those who have a high capacity to discern the veracity of the information and pitfalls to avoid based on the experience of those who failed to correctly differentiate true and misinformation.