跟读练习: Computational Linguistics: Crash Course Linguistics #15 - 通过视频学习英语口语
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Hi, I'm Taylor and welcome to Crash Course Linguistics.
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Computers are pretty great, but they can only do stuff that humans tell them to do.
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Counterintuitively, this means that the more automatic a human skill is, the more difficult it is for us to teach to computers.
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It's easy for us to teach a computer to calculate millions of digits of pi, or play chess.
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But get a computer to recognize which image contains a traffic light?
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Surprisingly difficult.
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The same thing goes for language.
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The parts that are difficult for humans, like learning lots of new words, are easy for computers.
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Humans, like understanding across typos and accents, or knowing if someone's sad or angry or joking, are really, really difficult for machines.
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Plus, language isn't just one task to teach.
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It's all the different things we've talked about throughout the series and more.
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Programming computers to process human language is called natural language processing, or computational linguistics.
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We rely on NLP for a whole range of tasks.
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search engines, voice -activated home systems, spam filters, spell checkers, predictive text, and more.
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Today we'll look at what NLP is and what makes language a difficult challenge for computers.
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Getting a computer to work with something as complex as language requires a lot of steps.
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First, we need to give the computer text to work with.
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We can input it directly, or get the computer to transform speech sounds, handwriting, or other physical text into digital text.
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We do that with speech -to -text, handwriting recognition, or optical character recognition processes.
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This step involves figuring out where the break between words and sentences go, such as the difference between a moist towelette versus a moist towelette.
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"owlet," or whether a small speck is the dot of an "i," a period, or a flock of dirt.
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Once it has the digital text, we then need the computer to figure out a the meanings of the words and b the relationship between them.
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It might use context to disambiguate between things like bank and blank, a riverbank and a financial bank, or common nouns and proper nouns.
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In this step, the machine figures out approximately what is being said.
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answer a question, translate it into another language, or find directions between two places.
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Each of these tasks also requires a different system.
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All of this data gets produced in some abstract form that the computer understands, like a mathematical equation or some lines of code.
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The last step is to re -encode that data into natural human language, which can involve text generation.
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Depending on what the user wants, the computer might need to produce the answer as speech, in which case it would use text -to -speech and speech synthesis.
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That's a lot of steps!
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The nice thing about splitting up natural language processing into different steps is
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that we can reuse parts of it for other tasks.
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For example, if we make one system that's good at text -to -speech for English, it can read aloud answers to questions, translations into English, and directions to go to places.
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We can also distinguish between what needs to be customized for each human language and what can always stay in computer code.
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That saves programmers and computers some time.
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also be useful by themselves.
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Automatic captioners may just do the speech -to -text part, screen readers may just do text -to -speech, and search or translation may start with text and skip processing speech entirely.
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A similar set of steps could work for signed languages too, although this technology is very underdeveloped compared to what's been created for a few big spoken languages.
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They could be something like signed -to -text, parsing signs, processing the results for a computer to work with, and rendering the output back into signs.
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that interoperated between signed and spoken languages.
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For example, a computer could take input in English and translate it to ASL, or vice versa.
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Just like with the thousands of spoken languages, though, each of the hundreds of signed languages would still need to be supported separately.
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One thing that won't really help is gloves.
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Let's head to the thought bubble to pop that bubble.
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You might have seen hyperbolic headlines about sign language translation gloves in the news throughout the years.
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They claim that these gloves can translate American Sign Language into English speech by recognizing the wearer's hand shapes.
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Unfortunately, these glove makers have made several fundamental misunderstandings about how sign languages work.
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One is that the grammar of signed languages isn't expressed just in the shape of the hand.
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Signed languages also include facial expressions and movements of the hands and arms in relation to the rest of the body.
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Two is that signed languages use far more signs than the 26 letters of the manual alphabet, which is all the gloves can detect.
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Plus, signed languages tend to use the manual alphabet to borrow technical words from spoken languages, not for core vocabulary.
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That's like making a translation system for English that only recognizes the words that come from Greek.
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people, but gloves can only translate from signs to speech, never from speech to a format accessible for deaf and hard of hearing people.
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Which is ironic, because the technology to produce written captions of speech already exists.
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Computational tools involving signed languages could one day exist, using other input sources that can actually access full signs,
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but they're never going to be any good if deaf people aren't consulted in creating them.
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And many deaf researchers have already pointed out that gloves are just never going to accomplish that.
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So let's say we've created a system that's pretty good at each of the steps involved in natural language processing, at least for one or two languages.
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Does the system understand language the way a human does?
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To answer that, let's pretend we've trained a rabbit to press buttons A, B, and C in order to get a treat.
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We could relabel those buttons "I want food," but that wouldn't mean that the rabbit understands English.
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The rabbit would press the same buttons if they were labeled something entirely unrelated.
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The same goes for a computer.
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If we tell a computer a few basic instructions, it can give the appearance of understanding language.
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But it might fall apart spectacularly when we ask it to do something more complicated.
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That's part of what makes teaching a computer to do language so tricky.
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Originally, people taught computers to do language tasks with long lists of more and more specific rules, such as "make a word plural by adding s," Wait,
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unless the word is child, in which case add ren instead, and so on, for other exceptions.
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More modern approaches to machine learning involve showing computers a whole bunch of data to train them on statistical patterns,
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and then testing how well they've figured out these patterns using a different set of data.
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A lot of recent leaps in natural language processing have come from a kind of statistical machine learning known as neural networks.
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Neural nets are based on a very simplified model of how neurons work in the brain, allowing which factors are the most relevant in the training data.
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But because they work out these factors for themselves, it's hard for humans to know exactly what patterns they're picking up on.
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Early in a neural net's training, it will make really silly, non -human -like errors, like returning a text EEEEEEE,
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because it's worked out that E is the most common letter in English writing.
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The machine will keep adjusting itself based on the training data, though, and eventually it starts returning things that look more like words.
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Well, almost.
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In any kind of machine learning, training data is really important, and there are two kinds of data we can use.
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The first is data with two corresponding parts that have been matched by humans, such as text with audio, words with definitions, questions with answers,
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sentences with translations, or images with captions.
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Using parallel data like this is known as supervised learning, and it's great, but it can be hard to find enough data that has both parts.
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After all, some humans have to create all of these pairs.
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The second kind of data has only one component, like a bunch of text or audio or video in one language.
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Using this kind of non -parallel data is known as unsupervised learning.
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It's much easier to find, but it's harder to use to train a computer, since it has to learn only from half of the pair.
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So researchers often use a mix of both: a smaller amount of parallel data to get things started, and then a larger amount of non -parallel data.
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semi -supervised learning.
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But none of this data just magically appears.
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It gets created or gathered by humans, and humans have all sorts of biases.
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Computer science researcher Harini Suresh created a framework to evaluate bias in machine learning.
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We can use this framework to see how bias affects the language tools we've discussed in this episode.
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First, historical bias is when a bias in the world gets reflected in the output the computer produces.
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For example, Turkish doesn't make a gender distinction in any of its pronouns, third -person singular, between he /she /it and singular they.
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So a translation system might pick a gender for pronouns when translating them from Turkish to English, making "he is a doctor" but "she is a nurse" from the same Turkish pronoun.
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This might reflect an overall tendency in the world, but our computer is still producing a gender bias.
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Next, representation bias is when some groups aren't as well represented as others in the training data.
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For instance, while researchers estimate that at least 2 ,000 languages are actively being used on social media,
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Only a few large languages are well represented in language tech tools.
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The rest are barely represented or left out, including all signed languages.
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When the features and labels in the training data don't accurately reflect what we're looking for, that's measurement bias.
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The text that has been translated into the most languages is the Bible, so it's often used as training data.
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But the style of language in religious texts can be very different from day -to -day conversation, and can produce strange results in Google Translate.
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Aggregation bias is when several groups of data with different characteristics are combined, and a single system isn't likely to work well for all of them at once.
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If we smushed all the varieties of English into training data for an English speech -to -text program, it could end up working better for standardized English than,
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say, African American English.
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program's success based on something users won't find useful.
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Researchers with an "English first" mentality might focus on whether a predictive text program predicts the next word,
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whereas the program that predicts the next morpheme would work better for languages with longer words and more morphemes.
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When a system was originally created for reasonable purposes but then gets misused after its release, that's deployment bias.
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Style analysis tools can be used to determine whether a historic figure wrote an anonymous anonymous whistleblowers.
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Being aware of these sources of bias is the first step in figuring out how to correct for them.
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Like the whole field of computational linguistics, addressing these biases is an active area of research.
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We have a responsibility to use our increased understanding of language
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through linguistics to deeply consider the effects we have on each other and the world we live in.
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This ethical consideration is especially important in computational linguistics because we interact with technology so much in our daily lives.
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Next time we'll talk about a much older kind of language technology, which is so common, we might not even think of it as a technology.
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writing systems.
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为什么要通过这个视频练习口语？
在这段视频中，泰勒讲解了计算语言学的基本概念，探讨了计算机如何处理人类语言的复杂性。通过模仿泰勒的说话方式，你不仅可以提升英语口语练习能力，还可以更深入地理解语言处理的逻辑。这种英语影子跟读的练习方式，能够帮助你更好地掌握语言的节奏和语调，提升语言理解能力。此外，短时间内集中练习有助于增强你的自信心，为将来与他人交流打下良好基础。
语法与表达的语境分析
- 被动语态的使用: 在讨论计算机处理语言时，泰勒提到“被赋予文本（text to work with）”。这展示了被动语态在技术性讨论中的重要性。
- 条件句的构成: 他运用了“如果我们制作一个系统...”这样的句型，帮助听者理解条件与结果的关系。
- 比较句型: 在讲解如何区分“bank”和“blank”时，泰勒使用了比较句型。这种结构能有效帮助学习者理解词义的细微差别。
通过使用这些结构进行英语口语练习，学习者可以在实际沟通中更清楚地表达他们的思想，增强他们的表达能力。
常见发音陷阱
在这段视频中，泰勒的发音清晰，但某些词汇可能对英语学习者构成挑战，例如“complex”和“recognition”。这些词在快速交谈时容易模糊，发音不准可能会导致误解。尤其是在不同的口音之间，词语的音调和重音可能会有所不同。特别是在学习提高英语发音时，注意这些词的发音和语调，即使是简短的练习也可以通过shadow speech方式进行，帮助学习者掌握标准发音。
选择合适的shadowing site进行练习，可以帮助你在实际交流中更有效地传达信息，并提高你对复杂语境中语言使用的敏感性。继续使用这些技巧，你会发现自己的口语能力会有显著提高！
什么是跟读法？
跟读法 (Shadowing) 是一种有科学依据的语言学习技巧，最初开发用于专业口译员的培训，并由多语言者Alexander Arguelles博士普及。这个方法简单而强大：您在听英语母语原声的同时立即大声重复——就像是一个延迟1-2秒紧跟说话者的影子。与被动听力或语法练习不同，跟读法强迫您的大脑和口腔肌肉同时处理并模仿真实的讲话模式。研究表明它能显着提高发音准确性，语调，节奏，连读，听力理解和口语流利度——使其成为雅思口语备考和真实英语交流最有效的方法之一。