0:00:00.107,0:00:03.926 ♪ [音乐] ♪ 0:00:20.880,0:00:22.077 - [Thomas Stratmann] 大家好! 0:00:22.077,0:00:24.268 在接下来的一系列视频中 0:00:24.268,0:00:26.858 我们将向你介绍一个[br]炫酷的新工具 0:00:26.858,0:00:30.414 来帮助你理解数据 0:00:30.414,0:00:31.981 那就是“线性回归” 0:00:32.885,0:00:34.668 假设你有这么一种理论 0:00:34.668,0:00:37.249 你发现外貌出众的人 0:00:37.249,0:00:39.067 好像总能得到特殊的优待 0:00:39.642,0:00:40.878 你在想 0:00:40.878,0:00:43.798 “还有什么地方[br]也能看到这种现象呢?” 0:00:44.132,0:00:45.637 对教师来说[br]这种现象也存在吗? 0:00:45.637,0:00:48.259 有没有可能[br]外貌出众的老师 0:00:48.259,0:00:50.010 也会得到特别优待呢? 0:00:50.350,0:00:53.899 学生们会不会[br]对这些老师更好 0:00:53.899,0:00:57.209 给他们打更高的学生评价分? 0:00:57.866,0:01:00.467 如果确实如此[br]外貌对评价分的影响 0:01:00.467,0:01:03.573 是很大还是很小呢? 0:01:04.159,0:01:07.519 假设有位教师刚刚开始[br]到一所大学上班 0:01:07.519,0:01:08.759 - [男人] 老兄,早啊 0:01:08.759,0:01:11.810 - 仅从他的外貌[br]我们能对他的学生评价分 0:01:11.810,0:01:13.371 做出怎样的预测? 0:01:13.940,0:01:17.216 由于评价分能影响加薪 0:01:17.671,0:01:21.709 如果这个理论属实[br]老师们可能会 0:01:21.709,0:01:24.519 采取一些令人惊讶的手段[br]来提高他们的得分 0:01:24.519,0:01:25.731 - [Lloyd Christmas] 耶! 0:01:25.731,0:01:27.461 - 如果你想弄清楚 0:01:27.461,0:01:30.801 更出众的外貌是否真的会[br]带来更高的评价分 0:01:31.441,0:01:34.450 你会怎样检验这个假说呢? 0:01:34.956,0:01:36.552 你可以收集数据 0:01:36.761,0:01:40.025 首先,让学生从1到10 0:01:40.025,0:01:42.076 给老师的外貌打分 0:01:42.076,0:01:44.807 由此你可以得出[br]这位老师的颜值平均分 0:01:45.229,0:01:48.552 然后你可以从25名学生处 0:01:48.552,0:01:50.421 收集这位老师的教学评价分 0:01:50.421,0:01:53.273 我们通过散点图 0:01:53.273,0:01:54.738 来同时查看这两个变量 0:01:54.981,0:01:57.419 我们用横轴表示外貌 0:01:57.852,0:02:00.589 纵轴表示教学评价分 0:02:01.223,0:02:04.903 例如,这一点代表着 Peate 教授 0:02:04.903,0:02:06.423 - [Bib Fortuna] De wana wanga. 0:02:06.423,0:02:08.811 - 他得到了3分的外貌分 0:02:08.811,0:02:11.866 8.425的教学评价分 0:02:12.084,0:02:14.958 这边的是 Helmchen 教授 0:02:14.958,0:02:16.797 - [Ben Stiller, "Zoolander"][br]帅到不像话! 0:02:16.797,0:02:18.721 - 他的外貌得分非常高 0:02:18.721,0:02:20.872 但评价分没那么高 0:02:21.101,0:02:22.283 你能看出规律吗? 0:02:22.283,0:02:25.533 当我们沿x轴从左向右移动 0:02:25.533,0:02:27.963 从难看向好看移动 0:02:27.963,0:02:31.186 评价分呈现出上升趋势 0:02:31.870,0:02:35.174 对了,我们在这个系列视频中[br]使用的数据 0:02:35.174,0:02:38.923 不是编造出来的[br]而是来自于 0:02:38.923,0:02:40.897 在德克萨斯大学做过的[br]真实研究 0:02:41.337,0:02:46.023 另外你可能不知道[br]“pulchritude”只不过是 0:02:46.023,0:02:47.880 “颜值”的另一种[br]比较高端、学术的说法 0:02:48.405,0:02:51.474 有些时候 0:02:51.474,0:02:55.594 用散点图很难判断出[br]两个变量之间的确切关系 0:02:55.594,0:02:59.104 尤其是随着我们[br]从左向右移动 0:02:59.104,0:03:01.318 数值的波动很大的时候 0:03:02.000,0:03:04.908 处理这种波动的一种方法是 0:03:04.908,0:03:08.144 画一条直线[br]穿过这团数据 0:03:08.144,0:03:10.775 让这条直线 0:03:10.775,0:03:12.613 尽可能贴切地概括这些数据 0:03:13.295,0:03:17.181 0:03:17.669,0:03:20.888 0:03:20.888,0:03:24.278 0:03:24.278,0:03:26.456 0:03:27.087,0:03:29.536 0:03:30.067,0:03:32.596 0:03:32.596,0:03:35.358 0:03:36.107,0:03:39.827 0:03:40.794,0:03:43.807 0:03:43.807,0:03:45.587 0:03:46.070,0:03:50.237 0:03:50.237,0:03:53.026 0:03:53.544,0:03:55.907 0:03:55.907,0:03:59.469 0:03:59.768,0:04:03.939 0:04:04.377,0:04:07.420 0:04:07.857,0:04:10.764 0:04:11.158,0:04:13.903 0:04:14.389,0:04:17.304 0:04:17.770,0:04:21.262 0:04:21.579,0:04:25.569 0:04:25.569,0:04:28.429 0:04:28.429,0:04:30.229 0:04:30.229,0:04:31.297 0:04:31.297,0:04:34.109 0:04:34.683,0:04:36.749 0:04:37.019,0:04:38.749 0:04:39.233,0:04:41.665 0:04:41.665,0:04:43.515 0:04:44.844,0:04:47.890 0:04:47.890,0:04:49.770 0:04:49.770,0:04:52.039 0:04:52.838,0:04:55.439 0:04:55.439,0:04:58.340 0:04:58.833,0:05:00.430 0:05:00.430,0:05:03.639 0:05:03.639,0:05:06.900 0:05:07.344,0:05:09.965 0:05:09.965,0:05:12.456 0:05:12.456,0:05:15.645 0:05:16.052,0:05:18.956 0:05:19.228,0:05:22.972 0:05:23.660,0:05:27.668 0:05:28.080,0:05:32.095 0:05:32.095,0:05:34.335 0:05:34.335,0:05:37.383 0:05:37.861,0:05:40.388 0:05:40.388,0:05:43.537 0:05:43.537,0:05:45.848 0:05:46.346,0:05:49.807 0:05:50.289,0:05:53.620 0:05:53.620,0:05:54.900 0:05:54.900,0:05:58.166 0:05:58.922,0:06:02.069 0:06:02.069,0:06:05.781 0:06:06.626,0:06:09.575 0:06:09.846,0:06:14.577 0:06:14.577,0:06:18.994 0:06:19.408,0:06:21.758 0:06:21.758,0:06:24.477 0:06:24.477,0:06:26.219 0:06:26.219,0:06:28.368 0:06:28.368,0:06:30.737 0:06:31.762,0:06:35.509 0:06:35.509,0:06:39.070 0:06:41.169,0:06:42.445 0:06:42.445,0:06:45.247 0:06:45.568,0:06:47.139 0:06:47.139,0:06:48.700 0:06:48.700,0:06:50.404 0:06:50.865,0:06:53.976 0:06:54.313,0:06:55.364 0:06:55.598,0:06:58.325 0:06:58.325,0:07:01.642 0:07:01.892,0:07:04.406