gilgamath


IMDb Rating by Sex

Thu 21 July 2016 by Steven E. Pav

The nerdosphere is in a minor tizzy over a putative bias in IMDb ratings for the new (2016) Ghostbusters film. It seems a bit odd to me, since IMDb ratings have always been horribly 'biased': If the question you are trying to answer is "If I am forced to watch this randomly selected movie, will I like it?", then IMDb ratings, and most aggregated movie ratings are difficult to interpret, very likely 'biased'. The typical mechanism by which a rating ends up on IMDb is that a person somehow gains an awareness of the film (this has been the major problem for studios since the end of the studio-theatre model seventy years ago), enough so to view the film; they are then more likely to rate the movie if they liked it, or liked it more than expected it, or really hated it. Those who had low to middling opinions of the film are less likely to rate it, and so you have the problem of missing data, without the simplifying assumption of "missing at random."

The Ghostbusters argy bargy (or one of them) is that reviews are suspected to be coming from people who have not seen the movie. This is possibly a problem for all reviews on IMDb, though less so for reviews appearing in streaming services, who know when you have seen a film. (The other argy bargy is that sexist and racist jerks have been harassing stars of the new film.) The analysis on five thirty eight is informative, but uses information (e.g. age and sex of the reviewers) that is not widely available, and which is volunteered by the reviewers. Given the IMDb mirror at my disposal, I can look for systematic biases for films based on sex, and will do so here.

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IMDb Rating by Actor Age

Wed 13 July 2016 by Steven E. Pav

I recently looked at IMDb ratings for Robert De Niro movies, finding slight evidence for a dip in ratings in his third act. I noted then that the data were subject to all kinds of selection biases, and that even in a perfect world would only reflect the ratings of movies that De Niro was in, not of his individual performance. I speculated that older actors might no longer be offered parts in good movies. This is something that can be explored via the IMDb mirror at my disposal, but only very weakly: if actors 'stopped caring' after a certain age, or declined in abilities, or even if IMDb raters simply liked movies with more young people, one might see the same patterns in the data. Despite these caveats, let us press on. read more


UseR 2016

Mon 11 July 2016 by Steven

Review of UseR 2016 conference

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Analyze This: Robert De Niro and IMDb Average Ratings

Sat 09 July 2016 by Steven E. Pav

I recently saw a plot purporting to show the Rotten Tomatoes' 'freshness' rating of Robert De Niro movies over the years, with some chart fluff suggesting 'Bobby' has essentially been phoning it in since 2002, at age 59. Somehow I wrote and maintain a mirror of IMDb which would be well suited to explore questions of this kind. Since I am inherently a skeptical person, I decided to look for myself. read more