PhrasePump algorithm

I’ve been using Phrase Pump for about a month now. In general I find it very useful for listening practice, but I have some concerns about it.

It might be good for you to describe the algorithm used for selecting the words used to find the example sentences. (I’m a language tool software developer myself, so I like to understand the algorithms of the tools I use.) Your help pages are surprisingly sketchy.

My first observation is that although each time there are new words and phrases coming up, it seems it is staying on the same words for a long time. I haven’t measured it, but it seems a long time. Is there a way to manage what words are used? Is it pure spaced repetiion? In the settings, I see a “New” control, which defaults to 15 %. Is that for new sentences or new words from which the sentences are drawn?

The Phrase Pump front page shows I have 1630 words that I’ve marked to learn (I only recently started to accumulate them. Previously, before using Phrase Pump, I would accumulate them from 1 or more videos, color coded for multiple videos, download them for one video for study in my flash cards, and then delete them, so I can start fresh.) It also says I am learning 36 words (3 months), 2 words (week), 1 word (day). The “learning” seems to imply “in progress”. Isn’t that way too slow a rate?

For the listening practice, when I study a sentence, if I understand a sentence before exposing the written form and translation, it seems like there should be a “knew it” button that would tell the algorithm to bring it back less frequently. It seems it repeats sentences I understand too often.

I don’t understand how it picks a few sentences for filling blanks or translating mode at the beginning. I would prefer to have the option of all one mode at a time, or mixing them up. One bug is that if the autotranslation comes out as “-”, these sentences are not excluded.

That’s my feedback for now. But thanks for your efforts in developing such a great tool!


Having used spaced repetition software for 20 years, I share your concerns and find the lack of engagement by LR staff on the matter very regrettable.

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I think I have a similar problem. I have been learning words through the Phrasepump for over 4 months now. Not a single word has moved to learnt in the last 4 months. I have been looking at the ‘half life’ and each time a word is reviewed it adds only a small amount (often 2 days). This means it takes a very long time for a word to become known - I’m not even sure what ‘half life’ a word needs to get to, to turn into a ‘learnt’ word.

It is great to have lots of repetiton, but I’m finding that it doesn’t show progress. For example I had a word that was to be reviewed in 13 days, then after 13 days, it’s half life changed to 15 after I had selected known in the quiz.

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I made a post about this a little while and agree with you completely.

I’m just adding my comment here too in the hope that Phrase Pump is the next part of LR to get an upgrade.

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I was able to find this Information related to the PhrasePump algorithm/process/method:

They merged the above “Flashcards” and “PhrasePump” at some point.

I also managed to find this on Reddit from 9ish months ago:

Sentences are read using the latest neural TTS. Items are scheduled using an advanced library, ‘Ebisu’.

I hope some of this helps!

P.S. I will update this if I find out any more information (things just kind of “pop up” on this forum sometimes that reveal a bit more of what LR is and how it works— /worked, in the case of some posts—unfortunately).

Thank you, that looks like a lot of people have the same problem. I still am having issues. I think they have accidently put +2 each time you review instead of x2. None of my words have moved to learnt yet. The one I photographed as being 13, then 15, is now at an interval of 18. It’s ridiculious. I hope they fix it soon as I do pay for pro and it doesn’t support good learning if things don’t move to learnt.

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