A concrete example from my deck: word added 2024-02-24, three reviews, now with an interval of 3.03 months. No 'again' answers; nice and easy! Another word, added 2024-02-29, not so good: 14 reviews and an interval of 15 days.

I think there are several factors contributing to forgetfulness with Anki for me, some of which might overlap with your experience:

A: not properly 'learning' the word in the first place. For me, 'learning' means using the word in context, studying its etymology (even if I do not intend to memorise that) and saying it out aloud. If I don't do that at the beginning, it won't really stick until I effectively start all over again.

B: 'learning' words on a bad day, or too late in the day. Even if I 'learn' the words properly, I need to have learnt them in Anki when I'm feeling moderately energetic. If I'm exhausted mentally or physically, my rigorous learning strategy doesn't seem to translate into memory. When I notice myself doing Anki reviews much slower than usual due to tiredness, I generally limit the review count and try to catch up when I'm fresh another day.

C: not being consistent enough with reviews. Both the time spent on each individual review and the time spent in total are important - 4 seconds per word is a good sign for me, and strictly 20 minutes a day in total. That allows me to keep up a pace of 12 new words a day very consistently.

Would love to hear which parts of this sound familiar to you, or what other things you've noticed for yourself!

This should (hopefully) get easier over time. From your dates there, it looks like the cards you have to re-learn often were only originally added 3 months ago? I think this should become easier for you in 6, 9, or 18 months – provided you continue to keep updated on the cards.

A. I definitely agree here. If I don't at least know understand a word to say, 30% confidence, I will never learn it, and will forever repeat it without making any progress. Personally I use images and sound to help make words stick in my mind. There's a lot of research about the effectiveness of imagery (see the "picture superiority effect.")

B. Ditto with #1. In scientific terms, this is called "encoding." Properly encoding things at the beginning has a big effect on your long term retention.

C. I do my reviews every morning while on the exercise bike. I use a gamepad to move through them more quickly, although I would technically be better with typing them out.

Also, as a side note, I have written a few blog posts on an old Substack about using Anki and AI tools:

https://neurotechnicians.substack.com/archive?sort=new

You might find the one about Using Images to Remember Things useful.

Whenever I fail a word, I try hard to find a reason for it. Most of the time it's interference - my answer resembles some similar word that I already know. I make a mental note about it, add this other word to the card. In most stubborn cases, some redundancy is good, I create another card for the same word in another context or just for a derivative of it.

Another thing that works for me is adding images (some of my cards just have a picture on the question side), and example sentences with the word in various contexts.

I have no doubt that spaced repetition is a biological reality in how our memories work but I haven't found a way to make it resonate for me.

The mistake most people make is simply adopting the "boring" flash card format of FRONT-BACK, and not incorporating other more creative types of cards. For example, question-answer, visualization, triggers, or unique images. ChatGPT is pretty useful for this, as you can get it to present the same information in a variety of different formats and contexts.