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statistics(統計)のsamplingのタイプについて

Cluster samplingとStratified samplingの違いが、いまいちよく分かりません。 1) An education researcher randomly selects and interviews 20 instructors at each community college in the state of California.    → 答えは、Clusterでいいですか? でも、あまり納得してないんです。上手く、解説してもらえませんか? 2) A market researcher surveys all the discjockeys in the 50 most populated counties across the U.S. concerning the types of music which are most requested. → これは、ほんとにどっちか分かりません。。。何を基本に考えたらいいんですか? これは、Random, Systematic, Convenienceのどれにも当てはまらないから、Cluster か Stratified sampling だと思ったんですが。 よろしくお願いします!!

みんなの回答

  • sen-sen
  • ベストアンサー率31% (66/211)
回答No.1

1) Stratified sampling community college別で層化して、それぞれのグループから、標本を無作為抽出を行っているから。 2) Cluster sampling 任意の50のcountiesを選択して、そのグループの構成標本を全て対象としているから。

chiesy
質問者

お礼

回答ありがとうございます。stratifiedとcluster違いは、グループ分けの後、それぞれのグループから無作為抽出をしてるか、そのグループの構成標本をすべて見ているかどうかという所ですね。教科書の、definitionをいくら読んでも、?だったので、日本語の説明が欲しかったんです。助かりました!これからも、sen-senさんにお世話になる可能性大ですので、よろしくお願いしますね!(笑)

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