 And my second guest is Professor Adam Wierzbicki, who's a professor at the Polish Japanese Academy for Information Technology, and a pioneer of research on web content credibility. He is also an expert on big data, web and data mining, and machine learning, or more general in data science. This title, the check-in in calculating and sort of organizing trusted sources of information, it's very interesting when you think of this issue of credibility. We are coming across many different websites in the web, who may or may not be credible, and it's not always very clear. Actually, in many cases, it is somewhere in the great area and it's very hard to decide whether you can trust that source or whether it's biased or it's just not okay. And with that, I would like to start the discussion by asking my first question to the professor about truth and credibility. Sometimes we think that those elements and those notions are interchangeable, credibility and being around. But I know for a fact that they are not. I would like to ask you how to tell them apart, and when you're out there in the cyber space, which one is the most important? All right, thank you. Thank you for this question. Well, I'd like to show you a few slides very briefly. Oh, if I can, because right now I don't have the ability to share the screen. But let me start with the definition of credibility, because that is probably what can start this discussion going. Basically, credibility is a property of information that we receive. And it is a property of information that makes us believe that this information is true. So you can think of it as credibility evaluation is something that we're doing all the time. Actually, whenever we communicate, we're doing this. And it is probably a part of our evolutionary background as human beings. On the other hand, truth, well, it is a completely different concept. It's actually independent of credibility. You can think of information which is true, but unfortunately it's not credible. On the other hand, you can think of information which is not true, but is credible. And this is the case of all successful fraud. So you can easily imagine examples of this kind, unfortunately. Well, you could treat truth as ideal or maybe as something which is unattainable depends on your epistemological opinion in reality. On the other hand, credibility is much more practical because this is something we're doing all the time. We're evaluating credibility all the time. You can think of credibility as a complex signal which depends on unfortunately many things. What you said about the web pages, credibility being ambiguous often that's because web pages are complex pieces of information with a lot of different things. For one instance, this is actually a division of credibility into different concepts that has been done by a very famous psychologist and media scientist, Carl Hofland, even into I think in the 1950s. It was quite a long time ago. So he divided credibility to source credibility, message credibility, media credibility, like you see here on the picture. And all of these can impact our credibility evaluations. When we receive some information or when you look at a web page, unfortunately, our credibility evaluation can be affected by a lot of different things as well, like by our knowledge, which is a very important factor. Or unfortunately, also by our social environment, for example, by peer pressure, right? You can think of the definitely peer pressure being a factor which impacts credibility. Sorry, I ran ahead with a couple of slides. Take a look at this picture. You can use credibility to define the things we're talking about, fake news or disinformation. For example, in this picture, we see a situation when we have a source. The source has a negative evaluation of its own message. So it doesn't believe its own message, but it depends for the receiver to believe this message, to find that the credibility evaluation of this message is positive. And this is the case of all this information and fake news out there, right? You can see that this can be defined. I'm using here the terminology from the European study that you're probably familiar with. Let's look at this case. It's a little bit different. Now, the original source's credibility version is positive and it intends the credibility evaluation of the receiver to be positive. Isn't that a perfect case where we actually don't need to do anything? Unfortunately not. So you can see that we're still investigating different kinds of information like, for example, the case of just forwarding fake news. This isn't the original source really. This should be a forwarding source in this case. But if this is the original source, then this could be misinformation, information which is wrong by mistake or malinformation as well. Now, what do you think about this? Isn't credibility still useful to evaluate how the source is making a credibility evaluation? And you think about it in this term, maybe the source is not sufficiently critical. Maybe the source is using reasoning that is based on a cognitive distortion. For example, I will give you an example. Let's say that we have a message, all immigrants are a threat to our society. Okay, so now the original source of this message might actually find it credible, might believe it. And if it does, it tells us something about the source. This source is using a generalized reasoning, which is a cognitive distortion. So perhaps what we should think about when we think about credibility and truth on the web, we should think about norms on evaluating credibility. Because psychology and media science has found a lot of things about how we should evaluate credibility basically. What is the right way of evaluating credibility? What is the wrong way? Based on that we can propose such norms and teaching such norms would be a very good way to help internet users to make sense of credibility. That's pretty much what I wanted to say using these slides, but perhaps I can also just answer some of your questions. This is extremely interesting. When I think of the credibility that you just have shown us, it is very much focused on how usual netizen would like to approach this issue, meaning he is searching that the internet is discovering certain websites he serves. But this is a kind of approach that tells you which of the sources you're currently reading is credible or not.