I just found this 2009 research paper written by a group of statisticians titled 'Does Your iPod Really Play Favorites?' (https://www.researchgate.net/profile/J

I just found this 2009 research paper written by a group of statisticians titled 'Does Your iPod Really Play Favorites?' (https://www.researchgate.net/profile/Jessica-Culhane/publication/227368948_Does_Your_iPod_Really_Play_Favorites/links/5766fb8b08aedbc345f5f4db/Does-Your-iPod-Really-Play-Favorites.pdf https://www.researchgate.net/profile/Jessica-Culhane/publica...). In this paper, they test different probability models to detect bias in iPod's shuffling algorithm and eventually conclude that: > Our statistical tests show the long-term occurrences of these events are within expectations under the assumption of a random shuffle." Regarding sorting by artists or groups, they found that: > We failed to find any evidence to support the claim of users like Steven Levy of favoritism of certain groups in the shuffle.