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Création de la leçon...
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So what is machine learning?
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In this video you learn a definition of what it is
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and also get a sense of when you might want to apply it.
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Let's take a look together.
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Here's the definition of what is machine learning that is attributed to Arthur Samuel.
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He defined machine learning as the field of study that gives computers the ability to learn without being explicitly programmed.
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Salva's claim to fame was that back in the 1950s he wrote a checkers playing program.
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And the amazing thing about this program was that Arthur Samuel himself wasn't a very good checkers player.
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What he did was he had programmed a computer to play maybe tens of thousands of games against himself.
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And by watching what sorts of board positions tended to lead to wins and what positions tended to lead to losses,
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the checkers playing program learned over time what are good or bad board positions.
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By trying to get to good and avoid bad positions, his program learned to get better and better at playing checkers.
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Because the computer had the patience to play tens of thousands of games against itself,
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it was able to get so much checkers playing experience that eventually it became a better checkers player than author Samuel himself.
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Now, throughout these videos, besides me trying to talk about stuff,
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I'll occasionally ask you a question to help make sure you understand the content here's one about what happens
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if the computer had played far fewer games please take a look
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and pick whichever you think is a better answer thanks for looking at the quiz and so
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if you had selected this answer would have made it worse
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then you got it right in general the more opportunities you give a learning algorithm to learn, the better it will perform.
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If you didn't select the correct answer the first time, that's totally okay too.
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The point of these quiz questions isn't to see if you can get them all correct on the first try.
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These questions are here just to help you practice the concepts you're learning.
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Author Samuel's definition was a rather informal one, but in the next two videos, we'll dive deeper together into what are the major types types of machine learning algorithms.
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In this class, you learn about many different learning algorithms.
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The two main types of machine learning are supervised learning and unsupervised learning.
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We'll define what these terms mean more in the next couple videos.
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Of these two, supervised learning is the type of machine learning that is used most in many real -world applications,
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and that has seen the most rapid advancement and innovation.
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In this specialization, which has three causes in total, the first and second causes will focus on supervised learning,
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and the third will focus on unsupervised learning.
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You might have also heard of reinforcement learning.
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This is another type of machine learning algorithm that I'll talk about briefly,
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but by far the two most used types of learning algorithms today are supervised learning and unsupervised learning.
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That's why we'll spend most of this class talking about them.
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The other thing we're going to spend a lot of time on in this specialization is practical advice for applying learning algorithms.
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This is something I feel pretty strongly about.
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Teaching about learning algorithms is like giving someone a set of tools
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and equally important
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or even more importance than making sure you have great tools is making sure you know how to apply them
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because you know what good is it
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if someone were to give you a state -of -the -art hammer
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or a state -of -the -art hand drill
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and say good luck now you have all the tools you
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need to build a three -story house It doesn't really work like that.
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And so too in machine learning, making sure you have the tools is really important.
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And so it's making sure that you know how to apply the tools of machine learning effectively.
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So that's what you get in this class, the tools as well as the skills in applying them effectively.
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I regularly visit with friends and teams in some of the top tech companies.
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And even today, I see experienced machine learning teams apply machine learning algorithms to some problems.
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And sometimes they've been going at it for six months without much success.
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And when I look at what they're doing, I sometimes feel like I could have told them six months ago that the current approach won't work.
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And there's a different way of using these tools that will give them a much better chance of success.
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So in this class, one of the relatively unique things you learn is you learn
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a lot about the best practices for how to actually develop a practical, valuable machine learning system.
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This way, you're less likely to end up in one of those teams
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that end up losing six months going in the wrong direction.
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In this class, you gain a sense of how the most skilled machine learning engineers build systems,
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and I hope you finish this class as one of those very rare people in today's world
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that know how to design and build serious machine learning systems.
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So that's machine learning.
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In the next video, let's look more deeply at what is supervised learning and also what is unsupervised learning.
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In addition, you learn when you might want to use each of them, supervised and unsupervised learning.
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I'll see you in the next video.

Vocabulaire et conseils d’expression pour cette leçon

Cette vidéo contient 64 phrases et 927 mots à répéter en shadowing. La partie parlée dure 5:36. Le locuteur parle à un rythme naturel d’environ 166 mots par minute, proche d’une conversation courante. 88 % des mots font partie des 3 000 mots les plus courants en anglais ; le reste mérite d’être vu avant de commencer.

Vocabulaire clé de cette vidéo

15 mots de la vidéo à retenir, avec leur prononciation et leur sens :

MotPrononciationSens
algorithm nom/ˈælɡəɹɪðm̩/algorithme
practical adjectif/ˈpɹæk.tɪ.kəl/pratique
select verbe/sɪˈlɛkt/choisir, sélectionner
skill nom/skɪl/habileté, compétence
define verbe/dɪˈfaɪn/déterminer
quiz nom/kwɪz/quiz
strongly adverbe/ˈstɹɔŋli/fort, fortement
deeply adverbe/ˈdi(ː)pli/profondément
equally adverbe/ˈiːkwəli/également
occasionally adverbe/əˈkeɪʒənəli/occasionnellement
rapid adjectif/ˈɹæp.ɪd/rapide
fame nom/feɪm/gloire, célébrité
innovation nom/ˌɪn.əˈveɪ.ʃən/innovation
fewer/ˈfjuː.ɚ/moins (de)
briefly adverbe/ˈbɹiːfli/brièvement, concisément

Les verbes à particule que vous entendrez

MotSens
end up verbese terminer, se finir

Prononciation à surveiller

Le locuteur utilise 16 contractions et formes réduites, comme I'll, we'll, you're. Prononcez-les sous leur forme courte, telles que vous les entendez.

  • Les sons « sh » et « zh »: occasionally /əˈkeɪʒənəli/, innovation /ˌɪn.əˈveɪ.ʃən/, patience /ˈpeɪ̯.ʃəns/, specialization [ˌspɛʃəlaɪ̯ˈzeɪ̯ʃn̩]
  • Mots longs — placez bien l’accent: occasionally /əˈkeɪʒənəli/, innovation /ˌɪn.əˈveɪ.ʃən/, specialization [ˌspɛʃəlaɪ̯ˈzeɪ̯ʃn̩], reinforcement /ˌɹiːɪnˈfɔːsmənt/

Comment s’entraîner avec cette vidéo

  1. Écoutez la vidéo en entier une fois sans parler et notez les mots que vous ne connaissez pas.
  2. Commencez à la vitesse 0,75×, répétez phrase par phrase, puis revenez à la vitesse normale quand cela devient facile.
  3. Enregistrez-vous et comparez avec l’original, en faisant attention à des mots comme algorithm, practical, select.

Qu'est-ce que la technique du Shadowing ?

Le Shadowing est une technique d'apprentissage des langues fondée sur la science, développée à l'origine pour la formation des interprètes professionnels. Le principe est simple mais puissant : vous écoutez de l'anglais natif et le répétez immédiatement à voix haute — comme une ombre suivant le locuteur avec un décalage de 1 à 2 secondes. Les recherches montrent une amélioration significative de la précision de la prononciation, de l'intonation, du rythme, des liaisons, de la compréhension orale et de la fluidité.

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