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.

    Since 2013,Torobo, a robotic are designed to test the limits of artificial intelligence, has had one ambition—to be admitted to the University of Tokyo, one of Asia's top-ranked educational institutions. Although equipped with an extensive database of textbooks and other teaching materials, Torobo has repeatedly failed to obtain the university's required minimum 80% score in the National Center Test, a yearly standardized entrance examination adopted by Japanese universities. This year was no exception.

    In early November, Torobo, along with millions of Japanese high school students, took a mock(模拟的)exam to prepare for the all-important standardized test.

    Torobo's total score of 525 out of 950, which was higher than the national average, was enough for it to get admitted to many other influential Japanese universities.

    However, its standard score of 57.1%, though 14 points higher than in 2015, still fell short of the minimum required for the University of Tokyo.

    A closer analysis of the results showed that Torobo was able to draw from its database to solve knowledge-based questions and ones involving complex mathematical calculations, but it had a hard time thinking independently, failing to comprehend multiple sentences and phrases to arrive at the logical conclusions. This weakness was reflected in its shabby English scores.

    Fortunately, the robot's creators have decided to free Torobo from its four-year sufferings. Noriko Arai, professor of the University of Tokyo who heads the team, says, “From the present results, we are able to evaluate the possibilities and limits of artificial intelligence. From now on, we will grow its abilities in the fields where it is doing well and aim to improve them to levels that can be applied in industry.” So while Torobo will never graduate from the University of Tokyo, it can still look forward to a bright future!

    Skeptics are a strange lot. Some of them refuse to admit the serious threat of human activities to the environment, and they are tired of people who disagree with them. Those people, say skeptics, spread nothing but bad news about the environment. The “eco-guilt” brought on by the discouraging news about our planet gives rise to the popularity of skeptics as people search for more comforting worldviews.

    Perhaps that explains why a new book by Bjorn Lomborg received so much popularity. That book, The Skeptic Environmentalist, declares that it measures the “real state of the world” as fine. Of course, another explanation is the deep pockets of some big businesses with special interests. Indeed, Mr. Lomborg's views are similar to those of some Industry-funded organizations, which start huge activities through the media to confuse the public about issues like global warming.

    So it was strange to see Mr. Lomborg's book go largely unchallenged in the media though his beliefs were contrary to most scientific opinions. One national newspaper in Canada ran a number of articles and reviews full of words of praise, even with the conclusion that “After Lomborg, the environmental movement will begin to die down.”

    Such one-sided views should have immediately been challenged. But only a different review appeared in Nature, a respected science magazine with specific readership. The review remarked that Mr. Lomborg's “preference for unexamined materials is incredible(不可信的)”.

    A critical (批判的)eye is valuable, and the media should present information in such a way that could allow people to make informed decisions. Unfortunately, that is often inaccessible as blocked by the desire to be shocking or to defend some special interests. People might become half-blinded before a world partially exhibited by the media. That's a shame, because matters concerning the health of the planet are far too important to be treated lightly.

    Thousands of years ago, Britain was covered by thick forests, home to many animals which no longer live in the United Kingdom. But all this has changed. Now the population of the United Kingdom has increased to sixty-five million. Three-quarters of Britain consists of fields, towns or cities. Although 25 percent of land is countryside, new methods of farming mean that there are fewer birds and small animals living in fields than ever before. Now, the United Kingdom does not have large wild carnivores (肉食动物). In Scotland, there are only 400 wildcats-Europe's rarest cats-but these are much smaller than wolves.

    Some people would like to change things, however! Some organizations and writers say that Britain needs to become more natural again. They suggest that trees and plants that grew in the United Kingdom before towns and cities were built should be allowed to grow again. They even say that large wild animals which have not lived in the United Kingdom should be helped to return and live wild. They call this "rewilding".

    Not everyone agrees. In the last twenty years, over one million trees which originally grew in Scotland have been planted and there are plans for more - but wild animals? Some people ask if wolves will attack sheep or even humans. They are also angry that rewilding might mean an end to walking in the hills which so many people enjoy. So far, there are no wolves or bears in Britain's forests - but soon there might be!

    Let children learn to judge their own work. A child learning to talk does not learn by being corrected all the time; if corrected too much, he will stop talking. He notices a thousand times a day the difference between the language he uses and the language those around him use. Bit by bit, he makes the necessary changes to make his language like other people's. In the same way, children learn to do all the other things without being taught to walk, run, climb, whistle, ride a bicycle…They compare their own performances with those of more skilled people, and slowly make the needed changes. But in school we never give a child a chance to find out his mistakes and correct them for himself. We do it all for him. We act as if we thought that he would never notice a mistake. If it is a matter in mathematics or science, give him the answer book. Let him correct his own papers. Why should we teachers waste time in such routine(日常的) work? Our job should be to help the child when he tells us that he can't find the way to get the right answer. Let the children learn what all educated persons must some day learn, how to measure their own understanding, how to know what he does not know.