WEBVTT 00:00.000 --> 00:12.480 So, I'm Evan Patton, I'm the lead software engineer for the MIT App and Venture Project. 00:12.480 --> 00:19.240 We've been an open source project for about 15 years now, thank you. 00:19.240 --> 00:23.400 And App and Venture is a web-based programming environment that you can use for making your 00:23.400 --> 00:25.200 own mobile phone applications. 00:25.200 --> 00:29.800 It uses a block-based coding environment, somewhere to other languages that we've seen in 00:29.800 --> 00:32.640 the Deverem today. 00:32.640 --> 00:36.560 And the product, though, at the end of the day, is an actual application that you can 00:36.560 --> 00:40.000 install and run on your robot device. 00:40.000 --> 00:44.360 So the project was started in 2008 at Google, it was eventually open source and is now 00:44.360 --> 00:46.600 managed and run at MIT. 00:46.600 --> 00:51.000 We've had over 23 million users use our system to build applications and they've made over 00:51.000 --> 00:54.320 113 million projects amongst them. 00:54.320 --> 00:58.920 We have about 1.4 million users per month, so quite a decent number of people around the world 00:58.920 --> 00:59.920 using it. 00:59.920 --> 01:05.200 But up the core of App and Venture's mission is this idea of computational action and the 01:05.200 --> 01:10.080 principal investigator of our project, Hal Abelson, says that young people really should 01:10.080 --> 01:15.040 be able to use computation as the means of having direct impact on their lives and their 01:15.040 --> 01:16.040 communities. 01:16.040 --> 01:19.760 And this is how they learn because they can actually build something that's going to make 01:19.760 --> 01:23.560 a difference that they can see. 01:23.560 --> 01:27.920 So App and Venture is used worldwide, it's used in pretty much every country on the planet. 01:27.920 --> 01:31.120 We've got millions of users and countries and hundreds of thousands and others. 01:31.120 --> 01:37.560 And again, as I mentioned, we have about 23 million users since we started. 01:37.560 --> 01:40.560 And there are a number of projects, just some examples. 01:40.560 --> 01:45.560 So one project is a group of students and Texas made an app for a blind student in their 01:45.560 --> 01:49.520 class to help him navigate around the school. 01:49.520 --> 01:55.320 Girl and Kentucky made an app to help remind her of grandfather with dementia when to take 01:55.320 --> 01:57.960 his medications. 01:57.960 --> 02:01.800 A group of teenage girls in Moldova made an app to help track water quality. 02:01.800 --> 02:05.040 So they would go in there and measure the quality of water wells and then capture that 02:05.040 --> 02:10.040 data in an app and then you could look up the water quality near you. 02:10.040 --> 02:15.120 Group of young girls in the Darby Slaman India made an app to help schedule time collecting 02:15.120 --> 02:18.560 water so that they were able to make sure that they got water in other resources they 02:18.560 --> 02:21.040 needed for household chores. 02:21.040 --> 02:25.280 And then some elementary school students in Hong Kong also made dementia related app to try 02:25.280 --> 02:31.040 to help their grandparents kind of keep track of the things they need to do day-to-day. 02:31.040 --> 02:33.240 Of course, it's not just restricted to young kids, right? 02:33.240 --> 02:36.280 Like, our goal is that everyone should be able to build an app. 02:36.280 --> 02:44.280 So we ran a global AI hackathon last year and this team from Brazil made this app called Zodengwe, 02:44.280 --> 02:48.440 which is basically they use teachable machine to train a model that they could then run 02:48.440 --> 02:53.960 inside of their application to detect whether mosquito larva were infected with the Dengwe virus 02:53.960 --> 02:54.960 or not. 02:54.960 --> 03:00.680 So I think a target, the eradication of the larva to try to reduce the spread of the disease 03:00.680 --> 03:05.320 and they were able to do that with 95% accuracy so that they could take a phone go out 03:05.320 --> 03:10.920 into the field, take a picture of some mosquito larva and then decide whether they need 03:10.920 --> 03:13.000 to administer pesticides. 03:13.000 --> 03:17.840 So it's a great way of how computational action be used to make a real difference with 03:17.840 --> 03:20.120 what I got the mentor. 03:20.120 --> 03:24.840 We also have a fairly robust community so you can go to community.appinventor.mit.edu 03:24.840 --> 03:30.040 where we have people offering help as well as extensions and things like that. 03:30.040 --> 03:35.040 So briefly, I'm just going to show app inventor, I know I showed pictures in the slides, 03:35.040 --> 03:42.160 this is an app that I was working on earlier. 03:42.160 --> 03:45.320 And what you do is you have this little companion app that runs on your phone as you can 03:45.320 --> 03:48.040 see broadcast on screen there. 03:48.040 --> 03:52.920 And then this is going to connect up and it's going to establish a session between my phone 03:52.920 --> 03:56.200 and the app in my browser. 03:56.200 --> 04:00.760 And this is typical of what you might want to do if you are using an external device 04:00.760 --> 04:01.760 via Bluetooth, right? 04:01.760 --> 04:05.640 So if any of you have people here used Bluetooth before for various things like actual 04:05.640 --> 04:07.840 programming Bluetooth a little bit. 04:07.840 --> 04:13.160 So internally underneath Bluetooth, you have all these UUIDs of things as you can see here. 04:13.160 --> 04:17.920 Here are the UUIDs for talking to a micro bit and I've got my little micro bit connected 04:17.920 --> 04:19.760 here as well. 04:19.760 --> 04:21.560 And so this is what you may have to do. 04:21.560 --> 04:25.360 But app inventor, we want to try to make things a little bit easier to try to give those 04:25.360 --> 04:30.680 higher levels of abstraction so that it's not as difficult for people to make use of these 04:30.680 --> 04:32.000 devices. 04:32.000 --> 04:37.160 So in the context of this app, or I could go back, let me just go back here to my design. 04:37.160 --> 04:40.440 And you can see how things work in real time. 04:40.440 --> 04:45.080 I can, for example, let's say I want to make all these buttons fill the screen so I can 04:45.080 --> 04:48.520 just say, you know, fill parent. 04:48.520 --> 04:51.680 And then as I make my changes, you'll see that the phone updates automatically. 04:51.680 --> 04:56.160 So I can very quickly get a sense of what changes I'm making and how they're going to 04:56.160 --> 05:01.360 potentially affect what I see and how I interact with my application. 05:01.360 --> 05:02.520 But this is really messy, right? 05:02.520 --> 05:06.000 Like I don't want to have to deal with UUIDs and all that stuff. 05:06.000 --> 05:10.560 So in app inventor, we did come up with a way of making extensions to the system. 05:10.560 --> 05:14.360 And so that's what I want to dedicate the bulk of my talk to you today. 05:14.360 --> 05:18.760 There's just a proliferation of Bluetooth being able to devices these days. 05:18.760 --> 05:22.280 I've seen a whole bunch of them today walking around to some of the other devarums, some 05:22.280 --> 05:23.280 of the other workshops. 05:23.280 --> 05:28.200 So I thought it'd be a great opportunity to talk about how you can do this in app inventor. 05:28.200 --> 05:32.360 So in app inventor, because we're actually building real native apps at the end of the day, 05:32.360 --> 05:36.480 you're writing actual code underneath to make that happen. 05:36.480 --> 05:40.240 So extensions in app inventor are written in Java. 05:40.240 --> 05:41.640 Because of that, they're Android only. 05:41.640 --> 05:45.640 They're also political reasons why they're Android only. 05:45.640 --> 05:49.080 And you can use them both in live development environment and compile apps. 05:49.080 --> 05:55.520 So for example, by pop back here for a second, and I go back to the designer and I expand 05:55.520 --> 06:00.000 the extensions category, we have this Bluetooth low energy extension, which is one that we 06:00.000 --> 06:02.040 publish from our group. 06:02.040 --> 06:08.520 And then the microbit example, which is the one that we're going to go through today. 06:08.520 --> 06:16.920 And what I can do here, if I go back, is these are being loaded in live companion. 06:16.920 --> 06:19.320 That's the app that I just showed you on the screen. 06:19.320 --> 06:20.760 But you can also compile your apps. 06:20.760 --> 06:23.440 So it's beneficial to be able to do that. 06:23.440 --> 06:26.320 There's a caveat when you're building and designing an extension. 06:26.320 --> 06:30.440 If you need to add new Android permissions to make it work, you can only use it in 06:30.440 --> 06:32.040 the compile versions. 06:32.040 --> 06:38.240 And that just is something to do with how they Android system manages permissions. 06:38.240 --> 06:42.040 So if you're interested in building an extension for app inventor, there's really just two 06:42.040 --> 06:43.040 prerequisites. 06:43.040 --> 06:45.040 First, you need the JDK. 06:45.040 --> 06:47.640 Again, because we're talking about building Java. 06:47.640 --> 06:50.960 And then we use Apache ant for managing our build system. 06:50.960 --> 06:52.600 Again, it's a fairly old project. 06:52.600 --> 06:55.720 So things like Gradle didn't exist back then. 06:55.720 --> 06:59.160 And then there are a number of different ways you can design and build extensions. 06:59.160 --> 07:01.640 What I'm going to be showing today is the first one, building it actually in the source 07:01.640 --> 07:03.480 tree of app inventor. 07:03.480 --> 07:06.080 We provide an extension template, which is a little bit more lightweight. 07:06.080 --> 07:08.440 It makes it a little bit faster to build extensions. 07:08.440 --> 07:13.520 And then there have been a couple of open source projects on our community that other contributors 07:13.520 --> 07:18.400 have made, such as Russian fast, but I'm not going to go into those today. 07:18.400 --> 07:22.760 I think the rush posts is something like a thousand posts long at this point. 07:22.760 --> 07:30.360 Definitely a very robust discussion about how to use it and make it better. 07:30.360 --> 07:35.560 In terms of our extensions, if you actually look at one under a microscope, it's really 07:35.560 --> 07:37.200 just a zip file. 07:37.200 --> 07:38.920 And it contains the following items. 07:38.920 --> 07:42.840 You'll see an icon, for example, to show up in app inventor. 07:42.840 --> 07:48.360 And then we've got both the Java compile classes and the Android compile text file to be able 07:48.360 --> 07:53.560 to load it into the companion app, and then additional metadata for exposing the functionality 07:53.560 --> 08:00.600 in the blocks, and when you're building your applications. 08:00.600 --> 08:03.120 And so this is where the talk gets a bit code heavy. 08:03.120 --> 08:06.520 I have uploaded all the slides, so the pre-tox system. 08:06.520 --> 08:10.840 If you want, you can go and you can literally copy and paste all the code into a file and 08:10.840 --> 08:12.120 it will compile. 08:12.120 --> 08:17.560 But first thing you need to do is you need to be able to clone the extension repository 08:17.560 --> 08:21.960 because we're building an extension for Bluetooth. 08:21.960 --> 08:26.600 I've gone ahead and I cloned it by cloning the Bluetooth low energy extension branch from 08:26.600 --> 08:29.760 our extensions repository. 08:29.760 --> 08:33.480 And then this is sort of your standard Java pre-ample. 08:33.480 --> 08:34.480 You have to have a package. 08:34.480 --> 08:38.440 I created mine called microbit, and then I imported a bunch of standard dependencies that 08:38.440 --> 08:46.000 you need for app inventor, including some annotations and runtime utilities and things like that. 08:46.000 --> 08:49.000 And this is the most basic form of an extension. 08:49.000 --> 08:50.160 You have some metadata. 08:50.160 --> 08:55.360 You need to tell app inventor about both things itself, such as a version number, which 08:55.360 --> 08:58.640 is shown to the user if they need to know what version they're using. 08:58.640 --> 09:02.200 And you need to tell it that it's an extension, obviously, and then you can give things 09:02.200 --> 09:06.680 like a help URL, for example. 09:06.680 --> 09:10.240 And then you need to tell the system that's actually external to the system. 09:10.240 --> 09:13.880 By default, app inventor kind of assumes that everything you build in the source tree is 09:13.880 --> 09:18.640 intended for use and app inventor, and the cell is a known app quite. 09:18.640 --> 09:23.640 And then the rest of this is just a standard Java object. 09:23.640 --> 09:25.040 If you compile of this, it will work. 09:25.040 --> 09:30.000 You can go and you can run ant extensions in the build tree, and you will get an extension 09:30.000 --> 09:31.160 file out. 09:31.160 --> 09:33.440 It will not do anything useful, right? 09:33.440 --> 09:35.360 It just simply shows up. 09:35.360 --> 09:38.080 And then it's in your app, but you can't do anything with it, because we haven't given 09:38.080 --> 09:41.280 a functionality yet. 09:41.280 --> 09:44.720 So kind of going back and looking at this, right? 09:44.720 --> 09:50.720 So we have these UUIDs that the microbit folks have defined for interacting with a microbit. 09:50.720 --> 09:54.840 So what I did is I moved those over into Java. 09:54.840 --> 09:58.440 And we need to have a reference to our Bluetooth connection. 09:58.440 --> 10:01.960 So that's in there as well. 10:01.960 --> 10:05.680 And then when we think about app inventor components, we're really thinking about four different 10:05.680 --> 10:09.360 types of blocks that they use really interact with. 10:09.360 --> 10:12.760 And we're going to have to implement one of each of these to make the extension really 10:12.760 --> 10:13.760 work. 10:13.760 --> 10:18.800 So the one on the top left there is an event handler, app inventor's in a very vent driven 10:18.800 --> 10:19.800 system. 10:19.800 --> 10:22.720 There's all sorts of stuff happening on your phone, and you need to be able to spawn, 10:22.720 --> 10:25.840 or at least to be able to spawn to those events firing. 10:25.840 --> 10:30.080 So we can say we have a message received there from our microbit. 10:30.080 --> 10:32.360 Likewise, we may need to send a message. 10:32.360 --> 10:36.120 So we'll want to define a function block, like the one on the top right. 10:36.120 --> 10:40.000 And then we need to be able to manage our references to our Bluetooth connection, which 10:40.000 --> 10:46.120 is how we actually communicate with the microbit device. 10:46.120 --> 10:49.640 So when we're defining an event, it's very straightforward. 10:49.640 --> 10:52.880 Events are really the simplest blocks in app inventor. 10:52.880 --> 10:58.120 All you need to do in your function is say that it's a simple event. 10:58.120 --> 11:00.800 This case I'm defining the message received event. 11:00.800 --> 11:03.520 And we know that it's going to receive a message from the device. 11:03.520 --> 11:08.080 And an event dispatcher is this very special object, which is responsible for understanding 11:08.080 --> 11:13.720 all of the internals of how app inventor works and how to send an event to the blocks 11:13.720 --> 11:16.320 that are executing the result of that event. 11:16.320 --> 11:23.520 So inside of this block here, you would put the behavior you want to do when the messages 11:23.520 --> 11:24.520 received. 11:24.520 --> 11:29.960 And so app inventor, the event dispatcher, knows how to find that and run it. 11:29.960 --> 11:34.280 This is where you get some integrated interns of dealing with all the Bluetooth stuff. 11:34.280 --> 11:37.920 So here we have an on-receive handler from the Bluetooth system. 11:37.920 --> 11:41.240 And so we're just saying when we receive a message, we're going to dispatch that through 11:41.240 --> 11:47.280 that message received event that we saw earlier. 11:47.280 --> 11:50.960 But of course, we need to have a way of establishing that relationship. 11:50.960 --> 11:55.080 So when the Bluetooth connection is established, when we get this on-connected event, 11:55.080 --> 11:58.840 we need to register for strings from the microbit. 11:58.840 --> 12:02.200 And then likewise, because we want to be good citizens, when we disconnect, we want to make 12:02.200 --> 12:03.200 sure we unregister. 12:03.200 --> 12:10.240 So we're not leaving around, you know, handles that would be otherwise garbage. 12:10.240 --> 12:17.080 So the next block or the property blocks, here we've defined that we have an editor type 12:17.080 --> 12:19.720 for this particular block that's a Bluetooth low energy. 12:19.720 --> 12:22.600 So it only accepts Bluetooth low energy components. 12:22.600 --> 12:26.240 We don't want to hand it a button, for example, because how do you have a microbit 12:26.240 --> 12:27.240 talk to a button? 12:27.240 --> 12:31.160 It makes no sense, because the button exists on the Android phone, and the microbit exists 12:31.160 --> 12:34.160 on a microbit, it's a separate thing. 12:34.160 --> 12:38.000 And so we handle our connection listeners there. 12:38.000 --> 12:42.560 And so this will tell the system that we want Bluetooth. 12:42.560 --> 12:48.160 And then likewise, you have a getter block, and the properties can be categorized. 12:48.160 --> 12:52.240 So I've said here that a Bluetooth device is a behavioral thing, right? 12:52.240 --> 12:53.240 The other options. 12:53.240 --> 12:58.040 Appearance, clearly, there's no appearance here, because it's an external device. 12:58.040 --> 13:00.400 That's managed separately. 13:00.400 --> 13:03.040 And then our last block, as I said, is going to be our function block. 13:03.040 --> 13:07.480 We want to be able to send messages to the microbit. 13:07.480 --> 13:14.280 So when we get our connection, if it's not null, we can call this right string with response, 13:14.280 --> 13:18.920 give it our UUIDs, and then we'll have a right handler, which comes back. 13:18.920 --> 13:21.920 I'm going to skip that one because it's not really necessary. 13:21.920 --> 13:25.920 And then lastly, this message sent block is going to be dealing with the right handler. 13:25.920 --> 13:30.920 So after we write our message, we'll get a message back, and we can dispatch that through 13:30.920 --> 13:31.920 the events. 13:31.920 --> 13:37.040 So this is our final package extension. 13:37.040 --> 13:43.720 And if I go back here, I pop over to Emacs real quick. 13:43.720 --> 13:51.160 You'll see on the right hand side here, I've added all that code from all those slides. 13:51.160 --> 13:53.480 And so this is the final working extension. 13:53.480 --> 13:55.560 And then I had just previously run Ant here. 13:55.560 --> 13:59.680 It takes about seven seconds, because of course it's compiling every app and mentor component 13:59.680 --> 14:03.960 in this version that extension template I mentioned earlier, it cuts all that out, so it's much faster 14:03.960 --> 14:07.960 it takes less than a second. 14:07.960 --> 14:12.480 But that is what the actual compilation process looks like. 14:12.480 --> 14:21.120 So now if I go back, and let me resume my connection here, we'll show you actually working 14:21.120 --> 14:36.640 in progress, maybe, once again, just one end out, restart, okay, so, so now, like you would 14:36.640 --> 14:39.720 have had to do something with this previously, and you don't necessarily want a student 14:39.720 --> 14:40.720 to have to do this, right? 14:40.720 --> 14:42.840 They have to know what you, you IDs to use. 14:42.840 --> 14:47.800 They have to know that the strings they're sending are not UTS-16, or that the device doesn't 14:47.800 --> 14:51.480 want them in UTS-16, and all this other stuff, right? 14:51.480 --> 14:56.160 Like that is a little bit too much for someone who's just starting off with something like 14:56.160 --> 14:57.160 the micro bit. 14:57.160 --> 15:01.320 So we're just going to go and delete that. 15:01.320 --> 15:06.360 And then I've loaded my pre-compile version of the extension in here, we see those blocks 15:06.360 --> 15:09.640 that we just created in the slides. 15:09.640 --> 15:15.680 Instead, I can just drop in a send message block, and I should have saved my string from 15:15.680 --> 15:17.080 earlier, but that's all right. 15:17.080 --> 15:28.120 And we're just going to have to say hello, pause them, and then I can add my message 15:28.120 --> 15:31.440 received block that I defined. 15:31.440 --> 15:36.760 And as we said, it's going to receive this message as a parameter, and to keep things 15:36.760 --> 15:43.760 simple all I did is I created the label in my app earlier to display that message. 15:43.760 --> 15:50.760 Okay, I'm going to just make sure my connections live, too. 15:50.760 --> 15:54.760 I'm just going to change one of the colors of these buttons to make sure it updates. 15:54.760 --> 16:05.440 Okay, so I'm going to go ahead, and I'm going to, now the micro bit here, you'll see 16:05.440 --> 16:09.280 it's got this little frowning face, because nothing's connected to it. 16:09.280 --> 16:13.120 So I'm going to connect, and it should change us to a smiley face, because now it knows 16:13.120 --> 16:15.240 that it's connected. 16:15.240 --> 16:21.720 And then I'm going to send my hello fuzz to message, and it should start scrolling. 16:21.720 --> 16:25.960 The micro bit doesn't have terribly fast output, but that's okay for the purposes 16:25.960 --> 16:26.960 of video recording. 16:26.960 --> 16:28.960 So that's fine. 16:28.960 --> 16:29.960 And so now it's saying hello fuzz. 16:29.960 --> 16:33.480 And of course, we could program this app to say some different string or you could program 16:33.480 --> 16:35.640 it to ask the user for a string. 16:35.640 --> 16:39.240 We're just kind of trying to keep it simple for the demonstration. 16:39.240 --> 16:45.280 And if I program button A to say button A when I press it. 16:45.280 --> 16:50.080 So if I press this, we should see my screen update. 16:50.080 --> 16:55.720 And if I zoom in here, oops, why did that happen? 16:55.720 --> 16:56.720 There we go. 16:56.720 --> 16:58.560 You can see now my message says button A. 16:58.600 --> 17:04.320 So we've managed to reproduce the entire loop of going to and from the micro bit, but 17:04.320 --> 17:10.080 rather than having to worry about the complexity of managing these UUIDs, right? 17:10.080 --> 17:17.720 Instead of having to do this, the student can just, well, that's stuck. 17:17.720 --> 17:20.320 Okay, the student could erase all those blocks, right? 17:20.320 --> 17:21.800 We don't need them anymore. 17:21.800 --> 17:23.600 They're not useful to us. 17:23.600 --> 17:27.040 And so all of that complex logic we might have to write. 17:27.040 --> 17:32.160 All those extra blocks that the user would have to deal with go away. 17:32.160 --> 17:34.720 And so now we can just think about sending messages. 17:34.720 --> 17:38.840 We don't have to worry about managing all that connection stuff, right? 17:38.840 --> 17:41.760 And so that's extremely powerful. 17:41.760 --> 17:47.840 And so just to kind of wrap it up here, how we loaded this. 17:47.840 --> 17:51.840 So and I showed you that extensions panel earlier in the talk. 17:51.840 --> 17:54.440 What you do is you click on import extension. 17:54.440 --> 18:00.160 It will open up this little dialog where you pick your extension file from your file system. 18:00.160 --> 18:06.640 And then you'll say import and then it will load it up into Apple Mentor and show up in your palette. 18:06.640 --> 18:09.560 Here are those example blocks for reference. 18:09.560 --> 18:15.000 Again, just so that if you go back and repeat this, you have access to everything. 18:15.000 --> 18:19.000 And then just to wrap up with some resources, if you want to learn more, including seeing 18:19.000 --> 18:23.400 all of our actual teacher materials around using micro bit in your classroom with Apple Mentor, 18:23.400 --> 18:30.960 you can go to Apple Mentor.mit.edu and there's a whole IOT section in a data science section that's available for you. 18:30.960 --> 18:36.520 Building your apps, you can go to ai2.appymetro.mit.edu and that gives you the code editor. 18:36.520 --> 18:38.480 We were just looking at. 18:38.480 --> 18:42.200 We're open source under the Apache license so you can feel free to contribute. 18:42.200 --> 18:45.000 You can fork us on GitHub. 18:45.000 --> 18:48.840 The community I already mentioned, a great resource for building your own extensions. 18:48.840 --> 18:53.760 There are a lot of people there, publishing extensions are willing to help out new contributors. 18:53.760 --> 18:58.600 And lastly, if you have any other things that you might need for me, you can feel free to reach out to me. 18:58.600 --> 19:01.840 That's my email there at MIT. 19:01.840 --> 19:04.840 And so with that, I'll take in the questions you may. 19:05.840 --> 19:07.840 Thank you. 19:18.840 --> 19:20.840 No questions? 19:20.840 --> 19:33.840 Okay, so I can show you some more stuff. 19:33.840 --> 19:34.840 That's fine. 19:34.840 --> 19:38.840 I'm always good at showing stuff. 19:38.840 --> 19:41.840 So that's the fuzzdom stuff. 19:41.840 --> 19:42.840 I was giving this demo. 19:42.840 --> 19:49.840 This is not an IOT related demo, but it's one of our data science classroom materials. 19:49.840 --> 19:57.840 So if you're teacher and you're interested in teaching things like data science, this is a great little tutorial that we made. 19:57.840 --> 20:04.840 To help you teach students about things like lines of best fit and cleaning up data and doing data analysis. 20:04.840 --> 20:07.840 And of course, you could connect it with something like the micro bits. 20:07.840 --> 20:16.840 We do all sorts of workshops where, for example, we'll take a football and American football, but you could do it with one around one as well. 20:16.840 --> 20:20.840 And you attach the micro bit to it and throw it or kick it. 20:20.840 --> 20:25.840 And then you get the accelerometer data and the students can visualize the accelerometer data in the app. 20:25.840 --> 20:28.840 But I can come in here and I can make predictions. 20:28.840 --> 20:31.840 That's going to load up this prediction screen. 20:31.840 --> 20:40.840 I'm going to say show data and this is going to read some data that comes from a Google spreadsheet, which is the spirit lake spreadsheet. 20:40.840 --> 20:49.840 So somebody's been going out every year since the 1950s and counting how many days that particular lake has had ice on it. 20:49.840 --> 20:56.840 And so you get this kind of very rough idea of how that lake has ice coverage over the course of the year. 20:56.840 --> 21:05.840 But you'll note that there are these two points towards the bottom of the graph, which are zeros and those seem a bit odd. 21:05.840 --> 21:11.840 And so we have this anomaly detection algorithm that does a Z score based filtering. 21:11.840 --> 21:18.840 So if I click on that, I can see that these data points are really out of range. 21:18.840 --> 21:22.840 They're outside of the standard deviation by more than two standard deviations. 21:22.840 --> 21:26.840 And I can actually say, okay, well that's very interesting. 21:26.840 --> 21:30.840 But what if I figure out the line at best fit for this? 21:30.840 --> 21:37.840 If we figure that out and it does the calculation for us using the standard RSME, we have doing that. 21:37.840 --> 21:48.840 We'll find that eventually if this trend were to continue in the long term, we might expect that this lake will have no ice around the year 2175. 21:48.840 --> 21:51.840 But the students can say, well, wait a second, what about those zeros? 21:51.840 --> 21:52.840 Those are not good, right? 21:52.840 --> 21:55.840 Was there really no ice on the lake that year? 21:55.840 --> 22:00.840 Well, it turns out, in fact, the person wasn't able to go out that particular year. 22:00.840 --> 22:03.840 So they still recorded a zero, which was not great. 22:03.840 --> 22:05.840 But I can click on these and I can delete them. 22:05.840 --> 22:11.840 And now my trend line extends out to 2280, right? 22:11.840 --> 22:19.840 And so now it's like, okay, well, if we actually remove the bad data, we can see that we get this extension of when we think that the lake might not have any ice anymore. 22:19.840 --> 22:27.840 And another cool thing is, in app inventor, we have a lot of blocks when we talk about simplifying various things. 22:27.840 --> 22:30.840 Let me go find it here. 22:30.840 --> 22:34.840 So this is AI analysis button, which I'm going to click. 22:34.840 --> 22:46.840 And what this is doing is this is giving a prompt, they can construct a prompt and send the data from this spreadsheet off to a large language model. 22:46.840 --> 22:53.840 In this case, we're using OpenAI, but we have an assortment of different models including some like Lama that you could self host. 22:53.840 --> 23:04.840 But eventually it comes back with this explanation here of what it thinks is happening with the state of and the potential implications for what that is. 23:04.840 --> 23:15.840 And so students can start to tie together all these different aspects of statistics and data science and artificial intelligence and build it all into applications that they can impact edge and share with people. 23:15.840 --> 23:22.840 And so those are just some of the other ways in which we've been taking these really complicated things and making them very simple, right? 23:22.840 --> 23:29.840 Like just calling the interface for this large language model is one block, right? 23:29.840 --> 23:34.840 It's not constructing a JSON object or a whole series of JSON objects for the conversation. 23:34.840 --> 23:36.840 We manage all of that under the hood. 23:36.840 --> 23:41.840 And so you get this very high level interface for doing these very complicated tasks. 23:41.840 --> 23:46.840 And so that's one of the real powers of app and then turn what we're doing with these block languages. 23:46.840 --> 23:48.840 Thank you.