 To me, an expert is someone who has a great deal of skill and knowledge about a particular topic. They could have gotten that through a number of ways, but I think mainly experience, which is a great teacher, and it comes from learning. It could be from learning in a college, or it could be learning through books, whatever it takes for someone to acquire a certain amount of knowledge in a particular area. I believe that an expert is someone who has extensive experience and study in a particular area and has really lived that area long enough that they can adapt and understand and assess almost any situation that they're in. An expert is someone who knows things. Now that's pretty simple, but really it is somebody who knows things. The key is we all know things. So what context are we looking at? I think what makes an expert is somebody also who knows what they don't know. My judgment may carry more weight because I've done the hard work that is required to think critically about the subject that I'm talking about. Distinguishing characteristic of an expert, as opposed to someone who just has a passing interest in a subject or likes to think about a subject, is accountability. So if there are mechanisms in place by which this person's command of the field is tested or if there's a credentialing capability, so for example obtaining academic credentials or press credentials or credentials in a trade, that helps to distinguish between people who are true experts in a field from people who maybe have an interest but don't quite have the expertise, if you will, to be considered an expert. People who are perhaps technically amateurs, they don't have a PhD in history or they don't have a formal training, may have been practitioners for years and developed expertise. That too can happen. I can rely upon them because they have something that maybe I don't have. There are questions that you should always ask yourself whenever you come across a source on the internet. Why or what is the purpose of this source? What is the agenda behind it? What authority or credibility does the person who wrote it have? At the end of the day also, I do think life experience is a really important source of credibility as well. It's not just any single thing, it's a lot of different things that you need to look at almost simultaneously, which is why telling what is a good source or a bad source can be very challenging. It's not even easy for professionals like me, but I think it's something you can develop and get better at. This is another area where our institutions are quite valuable and so as you have sources that are well-credentialed, so for example in the field of journalism if you have various news outlets that have years and years of accountability and trust and respectability that they've built up, those sources are much more reliable than sources where people are expressing opinions but haven't passed through that lens of accountability in quite a rigorous way and therefore are generally less trustworthy sources when comparing these multitude of voices that we have access to today. For me to believe a source and find it as valid, I think it has to have a proven track record of truth and whether they have a track record of being accurate and as relatively unbiased as possible. Amateurs read the text, but professionals read the footnotes. If you really want to know how does this person know or how can they know what they claim to know, look at the scaffolding that they built their argument. Where did they get their information? Did they get it from other secondary sources in history, a secondary source is something that someone has used, a narrative someone has written from materials in the past. The primary sources are materials directly from the past, whether they're physical or textual materials. And so if you base your argument on those primary materials, that's much more convincing. If you're sifting other people's arguments about those materials, you haven't maybe exposed yourself in a way that would allow you to make reliable judgments. Just to measure the internal coherence and consistency of arguments is another way to do this. You just need to be able to learn how to distinguish between a logical, rationally advanced argument and something, again that is maybe just opinion. So when you see information for the first time from a source and maybe you don't understand that source, you want to cross check that information with other sources, particularly sources that have been shown to be reliable, sort of that instinct to cross check information as you come across it, if you're not certain in advance that it's perhaps dubious information I think is an important characteristic that we should all try to refine as best we can. Sometimes I can size up a situation quickly, other times it takes me a little bit more time because I try to understand how this person acquired that information or that skill, that knowledge, that expertise and then I have to make a judgment whether this is going to be helpful to me or not.