The online economy—from search to email to social media—is built in large part on the fact that consumers are willing to give away their data in exchange for products that are free and easy to use. The assumption behind this trade-off is that without giving up all that data, those products either couldn't be so good or would have to come at a cost.

    But a new working paper, released this week by Lesley Chiou of Occidental College and Catherine Tucker of MIT, suggests that the trade-off may not always be necessary. By studying the effects of privacy regulations in the EU, they attempted to measure whether the anonymization(匿名化) of search data hurts the quality of search results.

    Most search engines capture user data, including IP addresses and other data that can identify a user across multiple visits. This data allows them search companies to improve their algorithms(算法) and to personalize results for the user. At least, that's the idea. To determine whether storage of users' personal data improves search results, Chiou and Tucker looked at how search results from Bring and Yahoo differed before and after changes in the European Commission's rules on data retention(数据保存). In 2008 the Commission recommended that search engines reduce the period over which search engines kept user records. In response, Yahoo decided to strengthen its privacy policy by anonymizing user data after 90 days. In 2010 Microsoft changed its policy, and began deleting IP addresses associated with searches on Bring after six months and all data points intended to identify a user across visits after 18 months. In 2011 Yahoo changed its policy again, this time deciding to store personal data longer—for 18 months rather than 90 days—allowing the researchers yet another chance to measure how changes in data storage affected search results.

    The researchers then looked at data from UK residents' web history before and after the changes. To measure search quality, they looked at the number of repeated searches, a signal of dissatisfaction with search results. In all three cases, they found no statistically significant effect on search result quality following changes in data retention policy. In other words, the decision to anonymize the data didn't appear to impair the search experience. “Our results suggest that the costs of privacy may be lower than currently perceived,” the authors write, though they note that previous studies have come to different conclusions.

    Today just as technology changed the face of industry, farms have undergone an "agricultural revolution". On the farm of today, machines provide almost all the power.

    One of the most important benefits will be the farm computer. The computers help them keep more accurate records so they can make better decisions on what crops to plant, how much livestock (家畜) to buy, when to sell their products, and how much profit they can expect. Many computer companies have been developing special computer programs just for farmers. In the future, farmers will be able to purchase computer programs made to their needs. Because of the growing importance of computers on the farm, students at agricultural colleges are required to take computer classes in addition to their normal agricultural courses. There can be no doubt that farmers will rely on computers even more in the future. While the old-time farm depended on horse power, and modern farms depend on machine power, farms of the future will depend on computer power.

    Another technological advance which is still in the experimental stage is the robot, a real "mechanized hired hand" that will be able to move and, in some ways, think like a human being. Agricultural engineers believe that computer-aided robots will make big changes in farming before the end of the century. Unlike farmers of the present, farmers of the future will find that many day-to-day tasks will be done for them. Scientists are now developing robots that will be able to drive tractors, and harvest fruit. Even complex jobs will be done by robots. For example, in order to milk their cows, farmers must first drive them into the barn, then connect them to the milking machines, watch the machines, and disconnect them when they are finished. In the future, this will all be done by robots. The complete mobilization (活动) of the farm is far in the future, but engineers expect that some robots will be used before long.

    A group of people asked this question to a group of 4-to-8-year-old children. “What does love mean?” The answers were surprising. The children would answer like they did below.

    “When my grandmother hurt her knees, she couldn't bent (弯腰) over and paint her toenails (脚指甲) any more. So my grandfather does it for her all the time, even when his hands hurt too. That's love.” Rebecca–age 8

    “Love is when someone hurts you. And you get so mad but you don't shout at them because you know it would hurt her feelings.” Samantha–age 6

    “Love is what makes you smile when you're tired.” Terri–age 4

    “I let my big sister pick on (捉弄) me because my mum says she only picks on me because she loves me. So I pick on my baby sister because I love her.” Bethany–age 4

    “I know my older sister loves me because she gives me all her old clothes and has to go out and buy new clothes.” Lauren–age 4

    “Love is when Mommy gives Daddy the best piece of chicken.” Elaine–age 5

    “My mommy loves me more than anybody. You don't see anyone else kissing me to sleep at night.” Clear–age 5

    “You really shouldn't say ‘I love you' unless you mean it. But if you mean it, you should say it a lot. People forget.” Jessica–age 8

    How do young children learn to have good values? How can parents teach their children about the importance of kindness and patience? At a time when more and more parents worry about the violent images(暴力形象) their children see on TV, some are turning to fairy tales(童话).

    It is believed that fairy tales have a great influence on children because they describe the two sides of good and evil(邪恶) very clearly. When children hear the stories, they learn to care about others' feelings. In each tale, they can see that there are many different kinds of people in the world and that we all have a choice about what kind of person we want to be. We can choose to do good actions, rather than bad ones, in our lives.

    What kind of values can children learn from fairy tales? In The Princess and the Pea(《豌豆公主》), a poorly dressed girl, who insists she is a princess, is given a difficult test by the Queen. When she passes the test, we learn that her dream comes true because she stays true to herself. In The Little Mermaid(《小美人鱼》), the mermaid, who lives under the sea, wishes to be with the humans on land. Through her experiences, we learn about the importance of living with and accepting other cultures. In Pinocchio, a wooden puppet(木偶) turns into a boy when he finally learns how to tell the truth.

    Teaching values is the reason most often given for encouraging children to read stories. These fairy tales can teach children lessons about human relationships that are accepted around the world for many countries. This might be the reason why they have been around for so long and will not disappear any more soon.

    The month of March was a milestone for supporters of renewable energy in the U.S. For the first time, wind and solar power accounted for more than 10% of the country's electricity—up from less than 1% at the turn of the century. And total wind and solar power-plant capacity(发电量) is expected to grow more than 30% over the course of this year and next, according to the Energy Information Administration.

    Such forecasts have led many scientists and policymakers to think that moving a large part of the nation's power supply to renewable sources—as cities from Miami Beach to Salt Lake City have promised to do—may not be as far-fetched as once thought. But like any debate, there are dissenters, including those inside the federal government. Their argument is that the nation demands an uninterrupted supply of electricity and cannot count on sun, wind and natural gas to provide it. “You need solid hydrocarbons(固体碳氢化合物) on-site for rising peak demand,” Environmental Protection Agency administrator Scott Pruitt said on Fox Business in May, referring to the importance of coal as a power source.

    Many experts say the government's concern fails to account for how the power grid(电网) has improved in recent decades. Utility companies(公共事业公司) have developed innovative ways to move electricity from place to place to account for variation in weather. Battery technology can store power for use when renewable sources cannot operate, meaning solar power can be used on days when the sun doesn't shine. And the nation's vast supply of natural gas can be turned into usable energy with the flick of a switch.

    “I don't think 5 or 10 years ago I'd be comfortable telling you we could not sacrifice reliability when we're going to have 35% of our energy come from wind,” said Ben Fowke, CEO of the utility company Xcel Energy, at a recent conference. “I'm telling you, I'm very comfortable with that today.”

    Indeed, many parts of the country are already close to that reality. In some regions, like Iowa and Kansas, renewable energy supplies more than 25% of the electricity. The market has shifted so far in favor of natural gas and renewable energy that even the most concerted federal effort is unlikely to stop its growth. Any attempt to slow the growth of wind and solar will face strong pushback. “If anyone wants to do away with it,” Republican Senator Chuck Grassley told Yahoo News of the federal government's potential cuts to wind energy, “he'll do it over my dead body.”

    But the federal government could slow the acceleration—and with billions of dollars in private and public investments at risk, the pace of change matters. Decisions made today will shape the future of the nation's energy grid for decades to come.

    As smog forced students to stay home, the online learning industry saw a sharp increase in consumers.

    During the air pollution red alert from Dec. 8 to 10 last winter, the Beijing Commission of Education ordered all kindergartens, primary schools and middle schools to suspend classes (停课). But the commission urged that, "Teachers should guide students to make full use of digital materials and conduct online learning at home".

    According to the China Education and Research Network, the number of new users of 17zuoye. com, an online homework platform, tripled (增至三倍) on Dec. 8 compared to the previous day.

    Online courses companies also adopted special measures to meet students' demand for Internet learning during the red alert period. For example, New Oriental offered free online English classes for three days for school students as well as online question answering services.

    Recent years have seen the popularity of online courses increase sharply in China. Massive Online Open Courses (MOOC), for example, originated in the United States but have become widespread in China since 2013. Some Chinese universities, including Tsinghua University and Peking University, have started their own MOOC platforms. "MOOCs have enlarged the time and space of teaching, fired up learners' interest, helped more people benefit from high quality educational resources and accelerated reform in many aspects of teaching," an official at the Ministry of Education told China Daily.