It is necessarily a matter of estimation which is explained in somewhat more excurtiating detail in this Tax Court decision from 2009.

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Yesterday Nintendo revealed its new Wii U console was selling more slowly than it had anticipated, and today company President Satoru Iwata explained the issues to investors in more detail.

ENGADGET

As explained in this New York Times article, mistakes imprint longer and in more detail as perhaps a cautionary tale of what to avoid next time.

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