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  • I want to talk about Khan Academy.

  • If you haven't heard of it, you should definitely check it out.

  • One guy, Ah Sau Khan has made thousands of videos over 2200 at the moment.

  • Ah, on everything from math too history and, uh, also quite a few videos about science.

  • And, ah, there are a lot of things to love about Khan Academy.

  • First of all, everything's freely available through YouTube.

  • Um Khan's goal is to improve the education for all students and he is an exceptional teacher on absolutely fantastic speaker.

  • He also emphasizes mastery, which I think is very important.

  • So students in the program can only move on after completing 10 questions in a row correctly.

  • And he's also developed some activities and software.

  • And he's working with schools to tryto humanize the classroom to try Thio, help improve the quality of student teacher time.

  • And he's pushing Ah, the learning well beyond video area.

  • But I want to put that work aside for a moment and just focus on the millions of viewers who watch his science videos online.

  • You see, I'm skeptical that they actually promote some meaningful learning, and that's not just a comment about Khan's videos but a comment on science videos in general.

  • So let me explain that skepticism.

  • I wrote my PhD thesis on how to create films to teach science, specifically physics.

  • In a typical study, students access to a website where they took a multiple choice pretest.

  • The questions were something like.

  • Consider a basketball player shooting from the free throw line after the ball leaves his hand.

  • The force on the ball is a upwards and constant.

  • Be upwards and decreasing sea downwards and constant de downwards and decreasing or e tangent to the path of the ball.

  • Take a minute to think about which answer you would pick and what you think most other people would pick.

  • After the pre test students were randomly assigned to see one of several online videos.

  • The video is contained correct answers to many of the pre test questions.

  • For example, here's a clip.

  • Now consider a case where gravitational force is the only force acting on an object, while a juggling bull is in the well, ignore a resistance because it's so small.

  • Only one force acts on the bull throughout its flight.

  • This is the force of gravity, which is constant and downwards.

  • Gravity accelerates the bull in the downwards direction.

  • After being thrown up, bubble travel slower and slower upwards, its velocity goes through zero, and then it's spades up in the downward direction.

  • The whole time the bull is accelerating downwards.

  • Then it makes the jugglers hand.

  • Immediately after watching the roughly 10 minute video, the students took exactly the same test.

  • I also interviewed some students to see what they thought of the video.

  • The most common comments were that it was clear, concise and easy to understand.

  • The students also increased their confidence in the correctness of their answers compared to the pre test.

  • So what about how much they learned on the pretest?

  • The average score with 6.0 out of 26 after the video, the average was 6.3.

  • Well, what was going on?

  • I dug deep in interviews to find out.

  • It turned out students did not even correctly remember what was presented in the video that they had seen a few minutes earlier, one recalled in the video.

  • It said the ball is slowly decreasing in force, so therefore it stops at one point and then comes down.

  • What was worse?

  • Another told me it wasn't that hard to pay attention to because I knew already what she was talking about.

  • I hadn't told him about this six out of 26 yet, so I was listening.

  • But I wasn't really paying utmost attention.

  • What could be done about this?

  • Perhaps videos are just too passive a medium to attract attention for 10 minutes, even when you know you're being interviewed after.

  • But I see the problem a different way.

  • Typically, we think of education as informing students about things they are not aware of, like the French Revolution, for example.

  • But science presents a different challenge.

  • It is not that students know nothing about it, but that they already have plenty of ideas, most of which are, unfortunately wrong.

  • Scientifically speaking, they don't pay attention because they think they know it.

  • And then when asked what they saw, they falsely remember their own ideas as what was presented.

  • Is there a way to overcome this?

  • Well, I thought students might pay more attention and be able to understand if their ideas were presented in the video.

  • So one of the other videos involved an actor pretending to be a student with the most common misconceptions, which were illustrated.

  • Can you tell me what happens when a single rule goes around?

  • One well looks hand gives the ball of force that drives it upwards against gravity.

  • But as it goes up, this force gradually dies away until at the very top, it perfectly balances gravity, and then gravity winds of the bull falls down.

  • Mm.

  • He then discussed with the other dialogue participant Why the misconceptions in work and have a scientific idea deferred.

  • In interviews with students who watched this video, no one used the words clear, concise or easy to understand.

  • Most often, they said, it was confusing.

  • But on the post test, the average score nearly doubled to 11 out of 26.

  • When asked to rate how much mental effort they invested in watching the videos, students who saw the dialogue with misconceptions averaged a whole point higher than those who saw the explanation without misconceptions.

  • And it seems like it worked.

  • That increased mental effort translated into more learning.

  • So with the very TASI, um, films, I always try to start with the misconceptions.

  • How long does it take for the earth to go around the sun.

  • Wow, Die.

  • Obviously it is.

  • This is ah, representing the earth.

  • And this represents what you think, Yes.

  • How far apart are they?

  • Roughly roughly.

  • That is the following statement.

  • True waffles.

  • Humans lived at the same time as dinosaurs.

  • I'll say true, we really have to tackle these misconceptions.

  • Somehow, it seems if you just present the correct information, five things happen.

  • Number one students think they know it.

  • Two, they don't pay their utmost attention.

  • Three.

  • They don't recognize that what is presented is different to what they're already thinking.

  • And four, they don't learn a thing.

  • And finally, five.

  • Perhaps most troubling Lee, they get more confident in the ideas they were thinking before.

  • This is a vicious cycle that we have to find a way to break in.

  • Orderto have effective science education.

  • So the Khan videos are amazing and definitely a valuable resource for a science educators and perhaps people looking for a bit of review.

  • But for those who are just starting to learn science, I question whether it's going to be that valuable because it doesn't really question their misconceptions by the office and take one day to get it on the sun.

I want to talk about Khan Academy.

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カーンアカデミーと科学動画の効果 (Khan Academy and the Effectiveness of Science Videos)

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    林宜悉 に公開 2021 年 01 月 14 日
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