WEBVTT 00:00:00.150 --> 00:00:00.983 - [David] Raiders, hello. 00:00:00.983 --> 00:00:03.750 This video is about analyzing visual evidence, 00:00:03.750 --> 00:00:05.190 but let's cut right to it. 00:00:05.190 --> 00:00:07.740 It's also about vampires. 00:00:07.740 --> 00:00:08.790 (spooky music) (thunder booming) 00:00:08.790 --> 00:00:09.690 And we'll get to them, 00:00:09.690 --> 00:00:11.715 those cape wearing, widows peaked wonders 00:00:11.715 --> 00:00:13.470 of the mountains of Transylvania. 00:00:13.470 --> 00:00:18.470 But first, what do we even mean by visual evidence? 00:00:18.780 --> 00:00:20.220 Like textual evidence, sure, 00:00:20.220 --> 00:00:21.783 we know what textual evidence is. 00:00:21.783 --> 00:00:23.460 It's written language. 00:00:23.460 --> 00:00:26.700 How do we know there's potassium hydroxide in my soap? 00:00:26.700 --> 00:00:27.690 It's on the label. 00:00:27.690 --> 00:00:30.870 Ah, but how much potassium hydroxide? 00:00:30.870 --> 00:00:33.330 Visual evidence can tell us. 00:00:33.330 --> 00:00:37.080 Visual evidence includes the graphs, charts, tables, images, 00:00:37.080 --> 00:00:40.530 and illustrations that authors use in their texts. 00:00:40.530 --> 00:00:42.150 Authors include visual evidence 00:00:42.150 --> 00:00:44.340 to help readers better understand ideas 00:00:44.340 --> 00:00:47.370 because sometimes words just don't cut it. 00:00:47.370 --> 00:00:50.310 Visual evidence can help strengthen a written argument 00:00:50.310 --> 00:00:53.640 and help express complicated ideas. 00:00:53.640 --> 00:00:56.310 So KOH, the potassium hydroxide, 00:00:56.310 --> 00:00:59.670 makes up 13.4% by weight of the soap. 00:00:59.670 --> 00:01:02.700 And sure it could list that percentage on the label, 00:01:02.700 --> 00:01:04.890 but to my eye, seeing the number 00:01:04.890 --> 00:01:07.200 and the pie chart is more helpful. 00:01:07.200 --> 00:01:08.400 I can see at a glance 00:01:08.400 --> 00:01:10.920 that potassium hydroxide, labeled here in red, 00:01:10.920 --> 00:01:13.590 only makes up a small part of my soap. 00:01:13.590 --> 00:01:16.200 This is useful because if there were a lot more KOH 00:01:16.200 --> 00:01:17.490 than there already is, 00:01:17.490 --> 00:01:19.890 the soap would burn my skin when I used it. 00:01:19.890 --> 00:01:22.920 Soap chemistry, visual evidence at work. 00:01:22.920 --> 00:01:26.550 Oftentimes, you will be asked to evaluate visual evidence 00:01:26.550 --> 00:01:28.020 to see whether it supports 00:01:28.020 --> 00:01:30.330 or challenges an argument in a text. 00:01:30.330 --> 00:01:32.700 This is something you'll have to do in many classes, 00:01:32.700 --> 00:01:35.850 history and science classes as well as English. 00:01:35.850 --> 00:01:38.340 And questions about this particular skill are common 00:01:38.340 --> 00:01:40.110 on standardized exams. 00:01:40.110 --> 00:01:42.540 So this brings us to vampires 00:01:42.540 --> 00:01:46.080 and specifically a very complicated idea about vampires 00:01:46.080 --> 00:01:50.039 that some Norwegian researchers wanted to test in 1994. 00:01:50.039 --> 00:01:54.120 Does garlic scare vampires away? 00:01:54.120 --> 00:01:55.350 This is a real study. 00:01:55.350 --> 00:01:58.020 They said something like, according to folklore, 00:01:58.020 --> 00:02:00.150 garlic repels vampires. 00:02:00.150 --> 00:02:01.710 We wished to verify this, 00:02:01.710 --> 00:02:05.940 but owing to the lack of vampires, we used leeches instead. 00:02:05.940 --> 00:02:09.210 Leeches, the real life blood sucking worms. 00:02:09.210 --> 00:02:12.210 So like vampires, kinda. 00:02:12.210 --> 00:02:13.890 Based on the data, 00:02:13.890 --> 00:02:16.950 does garlic actually keep vampires away? 00:02:16.950 --> 00:02:20.450 Remembering that leches here are our stand-ins for vampires. 00:02:20.450 --> 00:02:22.830 In a research setting, the leches were presented 00:02:22.830 --> 00:02:24.330 with a hand smeared with garlic 00:02:24.330 --> 00:02:26.520 and a clean hand with the expectation 00:02:26.520 --> 00:02:29.820 that they would attach themselves to one or the other. 00:02:29.820 --> 00:02:32.460 From our data, we conclude that the relationship 00:02:32.460 --> 00:02:35.670 between vampires and garlic is blank. 00:02:35.670 --> 00:02:37.710 So here's the graph. 00:02:37.710 --> 00:02:39.750 What conclusions can you make 00:02:39.750 --> 00:02:41.520 about the traditional relationship 00:02:41.520 --> 00:02:43.440 between garlic and vampires? 00:02:43.440 --> 00:02:46.590 What does this graph say happens? 00:02:46.590 --> 00:02:49.119 What does the visual evidence tell you? 00:02:49.119 --> 00:02:51.270 I'm going to put a little music on. 00:02:51.270 --> 00:02:53.730 Feel free to pause the video and discuss 00:02:53.730 --> 00:02:55.380 or make your own guesses. 00:02:55.380 --> 00:02:57.234 Alright, see you in a bit. 00:02:57.234 --> 00:02:59.734 (soft music) 00:03:06.680 --> 00:03:07.980 So the title of this graph is: 00:03:07.980 --> 00:03:11.310 How Long Do Leeches Take to Attach Themselves to a Hand? 00:03:11.310 --> 00:03:15.240 Right, and we have two bars on the horizontal axis, 00:03:15.240 --> 00:03:16.170 the X axis. 00:03:16.170 --> 00:03:19.440 One is with garlic, the other is without garlic. 00:03:19.440 --> 00:03:22.440 And over here on the Y axis, the vertical axis, 00:03:22.440 --> 00:03:24.840 we can see that the legend reads seconds. 00:03:24.840 --> 00:03:27.420 That's how many seconds the leches took to attach. 00:03:27.420 --> 00:03:28.890 This graph is potentially confusing 00:03:28.890 --> 00:03:29.820 because it might seem 00:03:29.820 --> 00:03:32.790 like the bigger bar is the better one, right? 00:03:32.790 --> 00:03:34.800 But this is response time, 00:03:34.800 --> 00:03:37.230 how long do they take? 00:03:37.230 --> 00:03:42.230 So 14.9 seconds over here versus 44.9 seconds over here. 00:03:42.630 --> 00:03:43.980 The shorter the response time, 00:03:43.980 --> 00:03:46.230 the faster the leach latches on. 00:03:46.230 --> 00:03:48.120 What can we conclude from this study therefore, 00:03:48.120 --> 00:03:51.510 what was the main conclusion of the study? 00:03:51.510 --> 00:03:54.270 Well, basically the leeches went 00:03:54.270 --> 00:03:58.380 for the garlic covered hand, the seasoned hand much faster, 00:03:58.380 --> 00:04:00.630 30 seconds faster on average than they went 00:04:00.630 --> 00:04:02.220 for the unseasoned hand. 00:04:02.220 --> 00:04:04.860 That means they like the garlicky hand more 00:04:04.860 --> 00:04:06.000 than the ungarlicky hand. 00:04:06.000 --> 00:04:07.710 And remember, tradition holds 00:04:07.710 --> 00:04:10.950 that garlic repels vampires, it sends them away. 00:04:10.950 --> 00:04:13.410 So from the result of this study, we can conclude 00:04:13.410 --> 00:04:18.410 that their tradition is wrong and vampires love garlic, 00:04:18.600 --> 00:04:22.200 if vampires and leeches are the same. 00:04:22.200 --> 00:04:23.610 Yeah, it's a bit of a leap. 00:04:23.610 --> 00:04:25.920 Maybe this particular case feels silly. 00:04:25.920 --> 00:04:28.590 Fine, but this is a useful skill. 00:04:28.590 --> 00:04:31.230 You will be asked to evaluate visual evidence 00:04:31.230 --> 00:04:32.640 to see whether it supports 00:04:32.640 --> 00:04:35.160 or challenges an argument in a text. 00:04:35.160 --> 00:04:37.020 A friend will send you an infographic 00:04:37.020 --> 00:04:38.430 about a political topic. 00:04:38.430 --> 00:04:40.620 You might look up stats for your favorite athlete. 00:04:40.620 --> 00:04:42.630 You might have to puzzle through a misleading graph 00:04:42.630 --> 00:04:43.770 on TV news. 00:04:43.770 --> 00:04:45.600 Understanding what data is trying 00:04:45.600 --> 00:04:48.780 to tell us is a core reading skill. 00:04:48.780 --> 00:04:52.290 Information, now it's got numbers in it, trademark. 00:04:52.290 --> 00:04:54.180 And now you've got numbers in you. 00:04:54.180 --> 00:04:55.013 Nice work. 00:04:55.013 --> 00:04:57.990 Watch out for leeches. You can learn anything. 00:04:57.990 --> 00:04:58.823 David out.