2. Recommender Systems

2.1. Recommender Systems: Explicit

  • Recommender systems are everywhere!

    • Youtube videos to recommend videos

    • Spotify, etc, to recommend music

    • Amazon to recommend books, other products

    • IMDB to recommend movies, TV shows

    • News items to read/watch

  • Those are all examples of situations where you are explicitly, knowingly providing information so that you can get recommendations.

2.2. Recommender Systems: Not So Explicit

  • Recommender systems are everywhere!

    • Pretty much any website with ads

    • Facebook, Instagram, Tiktok, etc to recommend content

2.3. How They Work

  • You already know the basics from Project 1.

  1. Collect information about your preferences.

    • Explicitly (ask for ratings)

    • Implicitly (watch your behavior – where you go, how long you look at things, what you “like” or otherwise comment on).

  2. Compare that to other people for similarities/opposites. (Collaborative Filtering)

    • Or possibly compare to yourself for things that get positive vs. negative response.

  3. Give you “recommendations” based on the matches.

    • Broadly speaking… ads are “recommendations” too

  • Of course, these are all far more sophisticated in real systems.

2.4. What Could Go Wrong?

  • Shouldn’t it always be a positive to get recommendations on things that you would like to see, buy, etc?

  • Better that than stuff you are not interested in, right?

2.5. What Could Go Wrong?

  • Pretty much by definition, a recommender system is trying to affect your behavior.

  • That can be good when its under your control. If you want a book or a song, then it has to be good to have recommendations for things that you would like, right?

  • Nearly always, the company has goals that benefit the company, with little regard for whether they benefit you.

    • Some companies are more ethical about that aspect than others.

  • Possibly your goals and the goals of the company doing the recommendation align… but that is more by happy coincidence.

2.6. What Could Those Goals Be?

  • For many commercial sites, the primary goal is to maintain use of the site.

    • Shopping sites want you to buy stuff.

    • Social Media sites pretty universally attempt to keep users attentive while they serve them ads.

      • Serving the ads is what makes their money for them.

2.7. What could go wrong?

  • Addiction

  • Information Bubbles

  • Misinformation

  • Financial loss

    • Shopping and gambling additions

  • Loss of privacy

  • User profiling/stereotyping

2.8. Social Media

  • Lots of stuff gets posted to social media

  • The companies complain that they can’t track it all.

  • But the issue is not what gets posted. The issue is what gets recommended.

  • The goal of a social media site is to keep you engaged.

    • Regardless of benefit to you, or not.

    • Provocative stuff keeps people engaged.

    • Often that is content that might be considered inappropriate for whatever reason.