The Report page has 3 sections:
The Completion metric represents how much of the deck you have studied. For the completion to reach 100% you must study all the cards in the deck at least once.
Retention measures how well you memorised your deck. It is calculated based on the score you achieved in each session and how many cards you have studied.
Let's say your deck has 10 cards and that the first time you studied this deck you flipped 4 cards and got all of them right. Your score for that session was 100%, but your overall retention is only 40%, after all, you didn't study all the cards yet (100% score x 40% completion).
Now, let's say that the next time you studied the same 4 cards, you got two of them right and the other two wrong. Your score was 50% (2 out of 4 right) while your retention was 20% (50% score x 40% completion). Your new overall retention was reduced, is now 30% (the average of the 2 sessions).
Retention is calculated over the last 3 sessions, so it becomes more accurate the more you study.
<aside> 🦊 To get a perfect retention of 100% you must study all your cards and have a perfect score in all of them 3 times in a row.
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A positive trend (green icon) means that your retention is improving with time.
A negative trend (red icon) means the retention is decreasing with time.
If you see a null trend (greyish icon with a slash) is because there's not enough data points yet to calculate the trend or it is not statistically significant.
<aside> ☝🏽 In case you are interested we use Pearson correlation coefficient to calculate the trend.
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This chart shows your best score of each day. So, if you studied the same deck 3 times in the same day you will see only one bar for that day, representing the highest of the 3 scores.
<aside> 🔑 If you study a deck more than once on the same day you will see only one result — the best one — plotted in the chart for that day.
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Below the chart you can see how many times in the period selected you studied the deck and how many cards you studied. So, if your deck has 10 cards and you studied all of them 3 times the number of cards studied will be 30.