2.37 Skew and movie ratings: IMDb (Internet Movie Database) publishes average ratings of movies worldwide. Anyone can log on and rate a film. What’s the worst-rated film of the more than 235,000 that are listed on IMDb? The Bollywood action-romance Gunday, which earned a rating of 1.4 on a scale of 1–10 (Goldenburg, 2014). Hardly any other movies even came close to that low rating. In fact, the average film is rated 6.3, and most of the movies garnered ratings between 5.5 and 7.2. Even though Gunday got pretty good critical reviews, it tanked on the crowdsourced IMDb. Why? Activists in Bangladesh harnessed social media to give it a bad rating. One posted, “If you’re a Bangladeshi and care enough to not let some Indian crappy movie distort our history of independence, let’s unite and boycott this movie!!!”

a. Based on what you know about the typical ratings on IMDb, is a histogram based on these data likely to be normally distributed, negatively skewed, or positively skewed? Explain your answer.

b. Is there more likely to be a floor effect or a ceiling effect for these data? Explain your answer.

c. Based on this story, are audience-generated IMDb ratings a good way to operationalize the quality of a movie? What might be a better way?