Even though reviews per author type were collected from a different platform (customer reviews from Amazon, expert reviews from LexisNexis Academic), we argue that the source does not determine or predict the type of author for the following reason: Many of these platforms list both types of reviews side by side, on the same platform.
expert reviews from sources like Rotten Tomatoes are not written by Rotten Tomatoes, but come from the same sources that we used for our study -e.g., major newspapers.