This video guide is going to show how to manage and visualise big data about world cities using a filter and popups. So to do this work, we need to sign into ArcGIS Online and click Map to open the map viewer, which you can see here. So we're gonna build this map from scratch really. So our first step is going to be to add and browse layers. And in the dropdown for ArcGIS Online, we're gonna type World Cities. Now, several layers appear with World Cities in their title, but we suggest you choose the one that's created by Esri, and then for that layer, click the + Add button, and the data will be added to your map. Now, the data has been loaded onto the map because we can see that in the legend on the right, but it's not appearing on the map. And the reason for that is that the creators of it have not made it visible at this world scale, probably to avoid cluttering. We can fix that by going to visibility, and you'll see a little slider here. If we just move that slider just to the left of world, all of the cities appear. And another thing that sometimes creators of the layers do is to change the transparency for various reasons, but we're going to reduce that to zero so that it makes the layer nice and bright and a little bit easier to see. So our world cities are shown as proportional circles, proportional to their populations. And now we can start doing interesting things with the layer. So we go to the Layers panel on the left, click that, and we can see the layer has appeared, World Cities. And what we're going to do in that is just check and see that we can use the visibility buttons. So you'll see a little eye here. If I click it once, it makes the layer disappear, but it's only temporary, if we click it again, it reappears. So just practise using that so that you know how that works. And then make sure you leave it on for the next step. And that next step is to use the filter. The filter is on the right. We're going to click Filter to open the panel for filter. And then we're going to click Add new to add a condition for our filter. And in the top panel of the Condition, we have a dropdown showing fields we can select. So we're going to look at the dropdown there and scroll down till we see the one which says population. Then we have the actual condition itself. We're going to leave that as it is, is at least, we're gonna change the number here to 4 million, four with six zeros after it. And then we save that condition. Watch what happens. The filter has hidden all the cities that are under 4 million people, so we can only see the ones that are at least 4 million. This means that we have decluttered the map and managed it so that we're just seeing the very biggest cities in the world. We can also change the visualisation by looking at basemaps. So if we look at the contents panel on the left and click the Basemap gallery, we can look for a basemap that will improve the visualisation still further. I'm gonna suggest you look at this one called Dark Grey Canvas. What's the difference? So the darker basemap really helps the proportional circle symbols to stand out quite a lot more 'cause the contrast is greater. So you might want to experiment with some different basemaps to see which ones provide the most effective visualisations. And having done some good work here, we don't want to lose it. So let's save our map by clicking Save and open. We're saving the map for the first time, so we click Save as. And let's call this one Urbanisation. Then we click Save, and it will save the map for us into our content. With our map saved, we can then check out the legend and we can see we've got the legend on the left, or key to help us interpret the proportional circles. We can also click the popups by clicking the symbols and we'll see the names of the cities. We can tidy up these popups and we'll see how to do that in a moment. If you get a whole group of them together, as you can see around China, a whole lot of cities over 4 million, you can click through the popups with the small arrow at the top of the popup or you can zoom down to have a closer look. Now, you may have noticed when you're clicking the popups, it was showing you all the attribute data associated with that city, but we may want to be selective in the same way as we've been selective using the filter. The way to do that is to click the layers panel so that we can tell the GIS which layer we want to configure. We click the three dots representing options so that we can see the properties panel on the right. And we move across to the other side to the settings toolbar and we click Pop-ups. And as well as the Pop-up panel on the right, we also see a Progress panel to show how we are changing the popups, which is quite useful. So the first thing we're going to do is alter the title. At the moment, it's showing city name and admin name. Let's change that. And we just literally can type a different formula of words to pick up the different fields. They have to be in curly brackets. You can choose them from the curly bracket dialogue here. But to save you time, just going to suggest you type city name, country name, that's abbreviated in the panel. And then we are going to check the fields list. And first of all, we've got all the fields showing, so we're going to delete them and then we're gonna add the ones we want. We're gonna customise what we show. And this is what we do. We click Add content, and we're going to add some text. So we click the Text box. And in the dialogue box, we can type this formula of words. So we're putting population equals, the curly brackets POP refers to the population from the database behind the map, then we type semicolon gap Status equals, and we're gonna find the status of the city. Watch what happens to the popup over here when we click okay. So the popups are configured to show the population of all the world cities and their status. So for example, Mexico City is the national and provincial capital. We're now going to save our work. So we go to Save and open and click Save. We've already saved our map once, so we just need to click Save very simply. We don't need to give it another name. Let's see what the spatial patterns on our map are showing. So we just close the dialogue boxes so they're not so much in the way, and we can start to examine those patterns. Perhaps the most striking aspect of the pattern of World Cities over 4 million is this massive concentration of them in Southeast Asia. We can click on the popups to see where they are. We just flick through a few of these. Now, we got Beijing, Guangzhou, Wuhan, Shanghai, and then we also see a similar sort of cluster in the Indian subcontinent. So we have cities such as Karachi in Pakistan, Mumbai, Delhi in India. We also see after that, probably the next biggest concentration would be in Africa. So cities like Lagos, South America, we have cities like Bueno Aires, but by contrast, we see very few of these largest cities in North America, in Europe, and in Australasia.