In 1885, a German named Hermann Ebbinghaus spent long periods memorizing lists of nonsense and testing himself on them. What he discovered has shaped the way we think about learning ever since: we forget fastest in the first hours and days after learning something, and more slowly after that. His forgetting curve can sound , yet it also contains some good news.
1885 年，德国心理学家赫尔曼·艾宾浩斯花了几个月时间，背诵一串串无意义的音节，并反复测试自己。 他的发现从此影响了人们对学习的理解：刚学会的东西，在最初几小时、几天里忘得最快，之后才慢下来。 这条「遗忘曲线」听上去让人泄气，其实也藏着好消息。
Each time we pull a word back from the edge of forgetting, the memory becomes stronger than it was before. Psychologists call this practice. Reading a word again feels productive, but trying to it, and struggling a little along the way, tends to do more for long-term memory.
每当我们把一个快要忘掉的词重新想起来，这段记忆就比之前更牢一些。 心理学家把这叫作「提取练习」。 把一个词再读一遍，感觉很有收获；可是试着把它回想起来、过程中稍微费点劲，往往更有利于长期记忆。
The second idea is . A word reviewed three times in one evening is usually forgotten sooner, while the same word reviewed across a week is far more likely to stay. A good moment to review is not while a word is still fresh, but when it has started to fade.
第二个要点是「间隔」。 一个晚上复习三遍的词，往往忘得更快；同一个词分散在一周里复习，留下来的可能性要大得多。 复习的好时机，不是词还新鲜的时候，而是它开始模糊的时候。
HiWord is built around these two ideas. When you study a card, you try to remember the meaning first, and only then turn the card over. How well you remembered decides when that card will come back. Words you know well return after longer and longer , while difficult ones return sooner, so your time goes where it is needed most. Practice then asks you to use the same words in different ways: matching, choosing, listening and spelling. Each of these is another small retrieval, and every retrieval makes the next one a little easier.
HiWord 正是围绕这两点设计的。 学卡片时，你先试着回想词义，然后才翻开卡片。 你记得怎么样，决定了这张卡下次什么时候回来。 熟悉的词，间隔越拉越长；难记的词，回来得更早。你的时间就花在最需要的地方。 接着，练习会换着方式练这些词：配对、选择、听辨、拼写。 每一种练法都是一次小小的提取，而每一次提取，都让下一次更容易一点。
So when a word feels half-forgotten, do not treat it as a failure. That moment of is when much of the learning happens. The same amount of time, spread across the week a few minutes at a time, usually does more than one long evening.
所以，当一个词似乎快要忘了，别把它当成失败。 学习往往就发生在这份费力里。 同样多的时间，分成每天几分钟、摊在一周里，通常比集中在一个漫长的晚上更有效。
