 |
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| directional sample | |||
| judgement sample; purposive sampling | |||
| purposive sample | |||
| spot sample | |||
| преднамеренная выборка: 1 短语, 1 学科 |
| 质量控制和标准 | 1 |
|
| |||
| directional sample | |||
| judgement sample; purposive sampling | |||
| purposive sample | |||
| spot sample | |||
| преднамеренная выборка: 1 短语, 1 学科 |
| 质量控制和标准 | 1 |