A lack of access to Cuba,says GAO, has made it difficult to obtain nationally representative data on audience size, and decision-makers have had limited information to assess the relative success or return on investment for each transmission method.

VOA: standard.2009.06.18

And to the extent these portray an unrealistic or unfair or biased perception of the world we could construct stereotypes that are faithful to the data we're getting but the data is not representative.

因为媒体,没有真实，公平，不偏不倚地反映世界,我们的刻板印象,就会根据这些信息来形成,但这些信息并不能以一概全。

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