6. The computer-implemented method of claim 4 , wherein determining the level of correlation between words in the portion of the companion item of textual content and words in the portion of the textual transcription comprises computing a correlation measure for a block of the companion item of textual content with respect to the textual transcription, the block comprising one or more portions of the companion item of textual content.
6. The computer-implemented method of claim 4 , wherein determining the level of correlation between words in the portion of the companion item of textual content and words in the portion of the textual transcription comprises computing a correlation measure for a block of the companion item of textual content with respect to the textual transcription, the block comprising one or more portions of the companion item of textual content. 20. The computer-implemented method of claim 6 , wherein determining that the level of correlation satisfies a threshold value comprises determining that the correlation measure for the block to which a portion of the companion item of textual content belongs, satisfies the threshold value.