According to Cathy Turner, a consultant forensic scientist at the FSS, the rapid advances in DNA technology have transformed the role of forensic scientists. "We've gone beyond corroborating allegations to using DNA and other techniques to provide fresh intelligence," she said. The swelling of the police national DNA database, which now holds profiles for 3.5m people, has in the last five years quadrupled the number of cases in which DNA is used. It provides police with some 3,000 matches to suspects every month.
The national DNA database has been criticised by privacy groups, who fear the privatised database could potentially be misused, but for police forces it is an invaluable resource, said Dr Fraser. "None of this evidence is infallible, irrefutable or unarguable. But it's pretty much the best evidence that'll ever be presented to the criminal justice system by some considerable way," he said.
4. What is the function of PLS? Illustrate the use of PLS by scientists.
5. Explain the sentence "The long arm of the law is getting considerably longer". (para.7)
6. What is the controversy over the use of the national DNA database?
Questions 7-10
The new SAT scores are out, and buried in them is a sign of hope for American education. True, the scores are actually a bit lower than last year's; the combined average for the SAT's math and reading sections fell 7 points, to 1021, the biggest decrease since 1975, when the score dropped 16 points, to 1010. But statistically speaking, a 7-point decline (out of a possible 1600 on those two sections) isn't much. It's less than the value of a single question, which is about 10 points. Also, the SAT was radically changed last year. The College Board made it longer and added Algebra II, more grammar and an essay. Fewer kids wanted to take the new 3-hr. 45-min. test more than once, so fewer had an opportunity to improve their performance. Scores were bound to slide.
But tucked into the reams of data the College Board included with the new scores was some wonderful news: 1 was wrong. In 2003 I spent six months tracking the development of the new SAT. I sat through hours of test-development sessions and even learned how to grade SAT essays. TIME ran my resulting story on its cover that October.
The story did make some predictions that turned out to be right. For instance, the new test favors girls more than the old one did. It is a long-standing tenet of testmaking that girls outperform boys on writing exams. For reasons I am not foolish enough to speculate about in print, girls are better than boys at fixing grammar and constructing essays, so the addition of a third SAT section, on writing, was almost certain to shrink the male-female score gap. It did. Girls trounced boys on the new writing section, 502 to 491. Boys still outscored girls overall, thanks largely to boys' 536 average on the math section, compared with girls' 502. But boys now lead on the reading section by just 3 points, 505 to 502; the gap was 8 points last year. What changed? The new test has no analogies ("bird is to nest" as "dog is to doghouse"), and boys usually clobbered girls on analogies.
