Experimental Design · 实验设计
| English | 中文 | Pinyin · 拼音 |
|---|---|---|
| treatments/ˈtriːtmənts/ | 处理 | chǔ lǐ |
| experimental units/ekˌsperɪˈmentl ˈjuːnɪts/ | 实验单元 | shí yàn dān yuán |
| placebo/pləˈsiːbəʊ/ | 安慰剂 | ān wèi jì |
| factor/ˈfæktə/ | 因子 | yīn zi |
| control/kənˈtrəʊl/ | 控制 | kòng zhì |
| randomization/ˌrændəmaɪˈzeɪʃn/ | 随机化 | suí jī huà |
| replication/ˌreplɪˈkeɪʃn/ | 重复 | chóng fù |
| control group/kənˈtrəʊl ɡruːp/ | 对照组 | duì zhào zǔ |
| blinding/ˈblaɪndɪŋ/ | 盲法 | máng fǎ |
The parts of an experiment
- An experiment imposes treatments on units and measures the result.
- Experimental units 实验单元: who or what receives a treatment (people = subjects).
- Treatments 处理: the specific conditions being compared (drug vs. placebo).
- The factor 因子 is the explanatory variable you control; the response is what you measure.
实验的各个部分
- 实验对单位施加处理，并测量结果。
- **实验单位：**接受处理的人或物（人 = 受试者）。
- **处理：**被比较的具体条件（药物对安慰剂）。
- 因素是你控制的解释变量；响应是你测量的东西。
Control, randomize, replicate
- Control 控制: keep other conditions the same so only the treatment differs.
- Randomization 随机化: assign units to treatments by chance — it balances out unknown differences.
- Replication 重复: use enough units (and repeat) so results aren't a fluke.
- These three principles are the backbone of every good experiment.
对照、随机、重复
- **对照：**让其他条件保持相同，只让处理不同。
- **随机化：**用机会把单位分配到各处理——它把未知的差异平衡开。
- **重复：**使用足够多的单位（并重复），使结果不是偶然。
- 这三条原则是每个好实验的骨架。
Control group and placebo
- A control group 对照组 gets no active treatment — a baseline to compare against.
- A placebo 安慰剂 is a fake treatment (sugar pill) that looks real.
- It separates the treatment's true effect from the placebo effect (improving just from believing).
- Comparing treatment vs. placebo isolates what the treatment actually did.
对照组与安慰剂
- 对照组不接受有效处理——作为比较的基线。
- 安慰剂是一种看起来像真的假处理（糖丸）。
- 它把处理的真实效果与安慰剂效应（仅因相信而好转）分开。
- 比较处理对安慰剂，就能分离出处理实际起的作用。
Blinding
- Blinding 盲法 hides who got which treatment, to stop expectations from biasing results.
- Single-blind: the subjects don't know their treatment.
- Double-blind: neither subjects nor the people measuring them know — the strongest guard.
- Blinding keeps hopes and hunches from leaking into the data.
盲法
- 盲法隐藏谁接受了哪种处理，以阻止预期使结果产生偏倚。
- **单盲：**受试者不知道自己的处理。
- **双盲：**受试者和测量他们的人都不知道——最强的防护。
- 盲法让希望与预感无法渗进数据。
Keep the three principles distinct. Control removes known outside differences; randomization balances the unknown ones; replication (enough units) ensures the effect is real, not chance. Randomization is what makes a cause-and-effect conclusion possible — control and replication alone, without it, are not enough.
把三条原则区分清楚。对照去除已知的外部差异；随机化平衡未知的差异；重复（足够的单位）确保效果是真实的、而非偶然。是随机化让因果结论成为可能——没有它，光有对照和重复是不够的。
Testing a new headache drug.
- Units/subjects: the patients. Treatments: new drug vs. placebo.
- Control group: patients on the placebo. Response: hours until pain relief.
- Double-blind: neither patients nor nurses know who got the real drug → unbiased measurement.
测试一种新的头痛药。
- **单位/受试者：**病人。处理：新药对安慰剂。
- **对照组：**服用安慰剂的病人。**响应：**多少小时后疼痛缓解。
- **双盲：**病人和护士都不知道谁拿到了真药 → 无偏的测量。
An experiment has experimental units, treatments, a factor (explanatory) and a response. Good design uses control, randomization, and replication; a control group (often on a placebo) is the baseline, and blinding (single- or double-blind) stops expectations from biasing results.
一个实验有实验单位、处理、一个因素（解释变量）和一个响应。好的设计使用对照、随机化和重复；对照组（常服安慰剂）是基线，而盲法（单盲或双盲）阻止预期使结果产生偏倚。
Splitting units into treatment and control · 把单位分成处理组和对照组
Randomly assign units to each treatment (and a control). · 把单位随机分配到各处理（以及一个对照）。
Match each principle to what it does. · 把每条原则与它的作用配对。
Control = known, randomization = unknown, replication = enough units. · 对照 = 已知，随机化 = 未知，重复 = 足够的单位。
A fake treatment (like a sugar pill) that looks real is a... · 一种看起来像真的假处理（如糖丸）是……
A placebo controls for the placebo effect. · 安慰剂用来控制安慰剂效应。
Neither the subjects nor the people measuring them know who got the real treatment. This is... · 受试者和测量他们的人都不知道谁拿到了真处理。这是……
Both sides blinded = double-blind. · 双方都设盲 = 双盲。
The group that receives no active treatment, used as a baseline, is the ___ group. · 不接受有效处理、用作基线的那一组是 ___ 组（填英文一词）。
The control group is the comparison baseline. · 对照组是比较的基线。
Randomly assigning units to treatments is what allows a cause-and-effect conclusion. · 把单位随机分配到各处理，正是允许因果结论的原因。
Random assignment balances confounders, enabling causal claims. · 随机分配平衡混杂因素，使因果主张成为可能。