The hypothesis-testing contains two parts here: one is the documentary study, the other is positive research.

假设检验从两方面着手，一是文献分析，另一为实证调研。

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Among the other DGA winners were Searching for Sugar Man director Malik Bendjelloul, who won the guild's documentary award for his study of the obscure singer-songwriter Sixto Rodriquez.

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The 2007 film Documentary Alice Neel by her grandson Andrew Neel is also a wonderful personal study of the artist's life.

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The ongoing study is like the science-y version of the "7-Up" documentary series -- with researchers checking in on the lives of the subjects at several-year intervals.

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