Road block： Driverless cars illustrate the limits of today’s AI

经济学人七月刊

Mary “Missy” Cummings, the director of Duke University’s Humans and Autonomy Laboratory, says that humans are better able to cope with such oddities because they can use “top-down” reasoning about the way the world works to guide them in situations where “bottom-up” signals from their senses are ambiguous or incomplete. AI systems mostly lack that capacity and are, in a sense, working with only half a brain. Though they are competent in their comfort zone, even trivial changes can be problematic. In the absence of the capacity to reason and generalise, computers are imprisoned by the same data that make them work in the first place. “These systems are fundamentally brittle,” says Dr Cummings.

brittle adj. /ˈbrɪtl/  

1.hard but easily broken 硬但易碎的；脆性的 •brittle bones/nails 易折的骨骼╱指甲

2.a brittle mood or state of mind is one that appears to be happy or strong but is actually nervous and easily damaged 脆弱的 •a brittle temperament 脆弱的性情

3.( of a sound 声音 ) hard and sharp in an unpleasant way 尖利的；刺耳的  •a brittle laugh 尖利的笑声

This narrow intelligence is visible in areas beyond just self-driving cars. Google’s “Translate” system usually does a decent job at translating between languages. But in 2018 researchers noticed that, when asked to translate 18 repetitions of the word “dog” into Yoruba (a language spoken in parts of Nigeria and Benin) and then back into English, it came up with the following: “Doomsday Clock is at three minutes to twelve. We are experiencing characters and dramatic developments in the world, which indicate that we are increasingly approaching the end times and Jesus’ return.”

Doomsday Clock 末日时钟    一座虚拟时钟，用于警示人类

Gary Marcus, a professor of psychology at New York University, says that, besides its comedy value, the mistranslation highlights how Google’s system does not understand the basic structure of language. Concepts like verbs or nouns are alien, let alone the notion that nouns refer to physical objects in a real world. Instead, it has constructed statistical rules linking strings of letters in one language with strings of letters in another, without any understanding of the concepts to which those letters refer. Language processing, he says, is therefore still baffled by the sorts of questions a toddler would find trivial.

toddler n. /ˈtɒdlə(r)/  a child who has only recently learnt to walk 学步的儿童；刚学会走路的孩子

How much those limitations matter varies from field to field. An automated system does not have to be better than a professional human translator to be useful, after all (Google’s system has since been tweaked). But it does set an upper bound on how useful chatbots or personal assistants are likely to become. And for safety-critical applications like self-driving cars, says Dr Cummings, AI’s limitations are potentially show-stopping.

Tweak /twiːk/  V/N 扭；拧；扯； 稍稍调整（机器、系统等）

Chatbots：chat-robot 聊天机器人

ponder v. /ˈpɒndə(r)/  [ V speech ] ~ (about/on/over sth) ( formal ) to think about sth carefully for a period of time 沉思；考虑；琢磨eg. She pondered over his words. 她反复琢磨他的话。

 Statesmen：政治家

 Keynote n. 基调；主旨；主音 vt. 给…定基调；说明基本政策 vi. 作主旨发言

Researchers are beginning to ponder what to do about the problem. In a conference talk in December Yoshua Bengio, one of AI’s elder statesmen, devoted his keynote address to it. Current machine-learning systems, said Dr Bengio, “learn in a very narrow way, they need much more data to learn a new task than [humans], they need humans to provide high-level concepts through labels, and they still make really stupid mistakes”.

Beyond deep learning

Different researchers have different ideas about how to try to improve things. One idea is to widen the scope, rather than the volume, of what machines are taught. Christopher Manning, of Stanford University’s AI Lab, points out that biological brains learn from far richer data-sets than machines. Artificial language models are trained solely on large quantities of text or speech. But a baby, he says, can rely on sounds, tone of voice or tracking what its parents are looking at, as well as a rich physical environment to help it anchor abstract concepts in the real world. This shades into an old idea in AI research called “embodied cognition”, which holds that if minds are to understand the world properly, they need to be fully embodied in it, not confined to an abstracted existence as pulses of electricity in a data-centre.

anchor /ˈæŋkə(r)/  

1.to let an anchor down from a boat or ship in order to prevent it from moving away 抛锚；下锚 •We anchored off the coast of Spain. 我们在西班牙沿海抛锚停泊。

2.[ VN ] to fix sth firmly in position so that it cannot move 使固定；扣牢；系牢 •Make sure the table is securely anchored. 务必要把桌子固定好。

3.[ VN ] [ usually passive ] ~ sb/sth (in/to sth) to firmly base sth on sth else 使扎根；使基于 •Her novels are anchored in everyday experience. 她的小说取材自日常生活经验。

embodied cognition ：体验认知

Biology offers other ideas, too. Dr Brooks argues that the current generation of AI researchers “fetishise” models that begin as blank slates, with no hand-crafted hints built in by their creators. But “all animals are born with structure in their brains,” he says. “That’s where you get instincts from.”

fetishize v. /ˈfetɪʃaɪz/  ( Bre also -ise)

1.to spend too much time thinking about or doing sth 迷恋于…；沉迷于…

2.to get sexual pleasure from thinking about or looking at a particular thing 对…有恋物癖

Slate n. [地质] 石板（slate的复数形式）；石板瓦 vt. 用石板瓦盖…；给…铺石板

Dr Marcus, for his part, thinks machine-learning techniques should be combined with older, “symbolic AI” approaches. These emphasise formal logic, hierarchical categories and top-down reasoning, and were most popular in the 1980s. Now, with machine-learning approaches in the ascendancy, they are a backwater.

Hierarchical adj. /ˌhaɪəˈrɑːkɪkl/ arranged in a hierarchy 按等级划分的；等级制度的• a hierarchical society/structure/organization 分等级的社会╱结构╱组织

top-down:自上而下，组织严密的； backwater：死水，停滞的状态

ascendancy n. /əˈsendənsi/ ( formal ) ~ (over sb/sth) the position of having power or influence over sb/sth 支配地位；优势；影响 • moral/political/intellectual ascendancy 道德影响；政治支配地位；智力优势

But others argue for persisting with existing approaches. Last year Richard Sutton, an AI researcher at the University of Alberta and DeepMind, published an essay called “The Bitter Lesson”, arguing that the history of AI shows that attempts to build human understanding into computers rarely work. Instead most of the field’s progress has come courtesy of Moore’s law, and the ability to bring ever more brute computational force to bear on a problem. The “bitter lesson” is that “the actual contents of [human] minds are tremendously, irredeemably complex…They are not what should be built in [to machines].”

courtesy /ˈkɜːtəsi/  

1.[ U ] polite behaviour that shows respect for other people 礼貌；谦恭；彬彬有礼 •I was treated with the utmost courtesy by the staff. 我受到了工作人员极有礼貌的接待。

2.[ Cusually pl. ] ( formal ) a polite thing that you say or do when you meet people in formal situations （正式场合见面时的）客气话，礼貌 •an exchange of courtesies before the meeting 会议开始前互致问候

IDIOMS 习语

1. courtesy of sb/sth

(1) ( also by courtesy of sb/sth ) with the official permission of sb/sth and as a favour 承蒙…的允许（或好意）  •The pictures have been reproduced by courtesy of the British Museum. 承蒙大英博物馆惠允，复制了这些画。

(2) given as a prize or provided free by a person or an organization 蒙…提供；赞助；赠送

•Win a weekend in Rome, courtesy of Fiat. 赢了就可以获得菲亚特公司提供的到罗马度周末的机会。

(3) as the result of a particular thing or situation 作为…的结果  •Viewers can see the stadium from the air, courtesy of a camera fastened to the plane. 由于飞机上安装有摄像机，电视观众可从空中鸟瞰体育场。

2. do sb the courtesy of doing sth：to be polite by doing the thing that is mentioned （做提及的事）对某人表示礼貌  •Please do me the courtesy of listening to what I'm saying. 请耐心听一听我的话。

3. have the courtesy to do sth：to know when you should do sth in order to be polite 知道何时该做…（以示礼貌）  •You think he'd at least have the courtesy to call to say he'd be late. 谁都会觉得他至少应该懂得打个电话说一声他要晚来。

Moore’s law：摩尔定律--是由英特尔(Intel)创始人之一戈登·摩尔(Gordon Moore)提出来的。其内容为:当价格不变时，集成电路上可容纳的元器件的数目，约每隔18-24个月便会增加一倍，性能也将提升一倍。换言之，每一美元所能买到的电脑性能，将每隔18-24个月翻一倍以上。这一定律揭示了信息技术进步的速度。

Computationaladj.  /ˌkɒmpjuˈteɪʃənl/ 使用计算机的；与计算机有关的

irredeemably/ˌɪrɪˈdiːməbli/无可救药地，不可挽回地

Away from the research labs, expectations around driverless cars are cooling. Some Chinese firms are experimenting with building digital guide rails into urban infrastructure, in an attempt to lighten the cognitive burden on the cars themselves. Incumbent carmakers, meanwhile, now prefer to talk about “driver-assistance” tools such as automatic lane-keeping or parking systems, rather than full-blown autonomous cars. A new wave of startups has deliberately smaller ambitions, hoping to build cars that drive around small, limited areas such as airports or retirement villages, or vehicles which trundle slowly along pavements, delivering packages under remote human supervision. “There’s a scientific reason we’re not going to get to full self-driving with our current technology,” says Dr Cummings. “This less ambitious stuff—I think that’s much more realistic.”

cognitive adj. /ˈkɒɡnətɪv/认知的，感知的

Incumbent /ɪnˈkʌmbənt/ n在职者；现任者；在任的，在职的

~ upon/on sb ( formal ) necessary as part of sb's duties 有责任；必须履行 •It was incumbent on them to attend. 他们必须出席。

full-blown：having all the characteristics of sb/sth; fully developed 具所有特征的；成熟的 • full-blown AIDS 完全型艾滋病

Trundle  v. /ˈtrʌndl/  [ adv./prep. ]

1. to move or roll somewhere slowly and noisily; to move sth slowly and noisily, especially sth heavy, with wheels （使缓慢、轰鸣地）移动，滚动 •A train trundled across the bridge. 一列火车隆隆驶过大桥。

2. [ V ] ( of a person 人 ) to walk slowly with heavy steps 沉重缓慢地走

TRUNDLE STH←→ˈOUT ( disapproving ) ( especially BrE ) to mention or do sth that you have often mentioned or done before 重提某事；重演故技