
MovieLens – Non-Commercial, Personalized Movie Recommendation System - wang42
https://movielens.org/
======
posborne
Here's the dataset they use. I have used this as part of developing and
testing the fitness of recommender systems in the past:
[http://grouplens.org/datasets/movielens/](http://grouplens.org/datasets/movielens/)

This predates some of my more recent work with the grouplens database, but
here is a parser I put together for the data awhile back:
[https://github.com/posborne/mlcollection/blob/master/mlcolle...](https://github.com/posborne/mlcollection/blob/master/mlcollection/datasets/movielens/movielensparser.py)

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dmix
This looks interesting, but I'm always sad to see consumer web apps still
requiring you to sign up before you can try it out. Missing out on so many
potential users. 1) sell the product then 2) ask for the customers info

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nathancahill
What would you expect to try out without an account? The whole point is using
your personal ratings of movies get new recommendations.

In most cases, I'd wholeheartedly agree with you, but in this case, the
experience is pretty tightly tied to having an account.

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dangson
Maybe ask the user to enter three movies they like and then give a
recommendation based off those three. I'd be more compelled to sign up once I
see the recommendation it returns isn't completely off the mark.

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Jedd
That's a lovely idea in theory, but in practice any recommendations made off
three data points are far more likely to discourage than encourage you from
ever using the service again.

Recommendation engines require a lot more training (by you) to be useful (to
you).

Worse yet, without the modest investment in time, including thinking up a new
password, there's a very high risk people will randomly click just to see what
the results are, which muddies the water for other users.

In any case, non-identified recommendation source data would need to be kept
in a silo until the user identified / validated they were not just fiddling
around. And that becomes a major mess to manage the data.

Having said that, I do respect people's right to tilt endlessly at windmills
in HN comments.

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prawn
Couldn't it be done via cookie?

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Jedd
Sure, but the big problem is not so much the tracking (IP, agent, cookie, etc)
but the small number of data points.

To properly evaluate the quality of the data you can get out of a
recommendation system, you need to put a useful amount of half-way decent data
into it.

It's a relatively small cost to create an account -- it took me less than 30s,
most of which was recording a new set of credentials in my password store.

One possibly intentional side-effect of requiring even a very simple
registration process is that it may reduce the amount of cruft going into the
engine. </speculating>

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amazon_not
All that is all good and well, but for two things:

\- it took me less time to input enough ratings to get useful recommendations
than to register

\- the registration asks for unnecessary information

Solution: if you don't want cruft in your dataset throw away recommendations
not linked to a registration. If the users finds the recommendations useful,
offer to save the profile by registering.

It's not like you are going to get any less cruft by forcing users
tonregister. The only difference is that you are going to end up with a lot of
throwaway accounts.

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nobody_nowhere
Oh wow, blast from the past. I remember rating hundreds of movies on this back
when collaborative filtering was fresh and new...

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pinko
Just signed in for the first time in years... the bulk of my ratings were done
in 2002!

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ivank
[http://criticker.com/](http://criticker.com/) is a good alternative. For each
movie, it shows you ratings from users sorted by their rating-similarity to
you. I've found it really helpful to see all the ratings in addition to
getting a predicted rating. I often use the individual ratings to figure out
whether a movie is in the cluster of what people-like-me watch, and also to
see whether opinion is unanimous or divisive.

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amazon_not
It might be great, but personally I don't like the UI. The throwback layout,
poor spacing and positioning spiced with non-relevant and distracting ads just
put me off. But then again that's just me, I bet somebody loves it.

I do however take issue with numerical scoring that is then changed to a value
based word score upon submission. People are notoriously bad at scoring things
on a 0-100 scale. It also begs the question why there is 0-100 scale when a
non-disclosed word score is applied anyway.

The final nail in the coffin was that they lost my activation email and won't
let me in without it. To add insult to injury there isn't an option to resend
the email. The only way to proceed is to email support and wait upon their
indulgence.

NEXT!

~~~
ivank
Yes, it's imperfect and a little ugly.

> then changed to a value based word score upon submission

Your numerical score is still there. You can pretty much totally ignore the
descriptors and think of the tiers T1-T10 as percentiles.

> begs the question why there is 0-100 scale

This lets you rate to any granularity you like to precisely order your movies.
After you have a large number of rated movies, you might want to tweak the
scores to bump a movie into a higher or lower tier.

Also, if you already have ratings in imdb, you can import them with
[http://www.criticker.com/?im](http://www.criticker.com/?im)

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nathanb
I rated 43 films, then selected "Top Picks for You" and got 0 results. So I
decided to not watch a movie and instead go for a walk. Which turned out to be
exactly what I needed. Five stars.

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wang42
Have you tried selecting the "warrior" mode? The same thing happened to me but
after I selected "warrior" mode, recommendations popped up.

Edit: It seems that the "wizard" mode is updated daily or so.

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amazon_not
Same here. The wizard mode seems broken. As soon as I rated more than a
handful of movies it started showing 0 recomendations.

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wang42
It seems that recommendations by the "wizard" mode are updated daily or so. I
signed up yesterday and got nothing with the wizard mode. It starts to show
promising results just now I checked.

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amazon_not
You'd think that they wouldn't make it the default mode then. Or at least warn
the user.

Regardless what the root cause is the end result is that it's broken from a
user perspective.

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pen2l
Despite there being so many of these sites, most of them kind of fail for me.

For instance... last night I was wanting to watch a movie, but the kids needed
to watch it too (as they can't be left unattended with me watching a movie in
the other room :)).

So I went off on a search for a movie to watch... with a rating filter -- it
needed to be either G or PG.

Nothing. No recommendation site, Netflix, or anything let me filter
movies/shows this way. Yes, you have the 'Kids' section on Netflix, but most
of the stuff there is deathly boring for adults, I was hoping for something
good for both kids and adults.

I ended up not watching anything.

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ddeck
Although not a personal recommendation site, instantwatcher.com allows you to
filter Netflix titles by rating and sort by a lot of other useful criteria
such as production year, rotten tomato rating etc.

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Harelin
Something like this would be useful if you could cross-reference your
recommendations with others. If I have a set of recommended movies, tell me
which movies are also recommended to members of my family, so that we can find
the one we are most likely to all enjoy.

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cryowaffle
Neat, I worked on this project while at the U of M under the instruction of
now passed John Riedl.

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aaronbrethorst
Shit, I hadn't heard that John Riedl died. I'm really sorry to hear it. I
never had a chance to take a class with him, but Professors Konstan and
Terveen were incredibly influential for me.

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dmoy
Riedl is the reason I have my job :( I would not be where I am without him.

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MichaelGG
Proof that Netflix doesn't need all that effort to deliver a laggy, annoying,
UI. Seriously, the core functionality is essentially the same. MovieLens seems
like it might replace Netflix for me. Not-terrible recommendations and a
decent UI. Though I've only been using it a few days so we'll see, but it can
barely end up _worse_ than Netflix eh?

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scottmcdot
Any way I can upload my IMDB ratings .csv to this?

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fayimora
I can't seem to get past the captcha :( Anyone else?

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wang42
Me too. It seems to depend on browser. I did not pass on Chrome but pass after
switching to Safari.

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fayimora
Very weird! I just tried in Safari and all I had to do was tick a checkbox as
opposed to identifying pancakes and street signs in Chrome.

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KerrM
Very cool, I wish they had a public API to query!

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grandalf
this has been one of my favorite sites for years.

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RodericDay
I'm torn. On the one hand, I just spent a few minutes rating about 100 films,
and the quality of the recommendations is so much better than Netflix's
garbage that it's mindblowing. As in, we've spent half an hour browsing
Netflix trying to find something to watch and settling for something meh,
whereas here I have a full page of recs with 5 minutes input.

On the other hand, I don't know if I'm very impressed with anything yet, the
recommendations seem obvious. It's more like a neat visual collection manager,
I'm not sure I "feel" anything crazy going on in the background beyond what
looking at IMDb best-of lists would produce. In other words, the value seems
to be in the Netflix-ish "cover collection" display, unconstrained by the
limits of their selection.

