Spaced repetition for Morse code: review what you miss
Spaced repetition means reviewing each Morse character on its own schedule: the ones you miss come back soon, and the ones you know come back less and less often. Your practice time goes where it does the most good, on the characters that are slipping, instead of on E and T, which you knew on the first day.
You can run it with a notebook and a pencil. The only hard part is being honest about what counts as a miss.
What spaced repetition is
Two ideas sit underneath it. First, what you do not use fades, so the aim is to review a character before it slips, not long after it has gone. Second, every successful review lets the next one wait a little longer. Put together, the rule is simple: review a new or shaky item often, review it less as it proves itself, and send it straight back to “often” the moment you miss it.
Behind this is what is often called the spacing effect: the same amount of practice spread across several days tends to stick better than the same practice crammed into one sitting. Spaced repetition is a way of organizing that spread so you do not have to keep track of it in your head.
For Morse, the item is a character, and knowing it means something specific. It is not remembering a row on a chart. It is recognizing the sound the instant it ends, or sending it cleanly without thinking. That is why learning by sound, not from a chart matters here too: the review has to be done by ear or by hand, not by reading.
Why weak characters should come back sooner
Plain random drills give every character the same share of time, but your errors are not spread evenly. They cluster on a few characters, often the ones that differ from a neighbor by a single element.
The arithmetic is unkind. If you are working on 40 characters and know 30 of them well, three in four characters in a random drill are ones you did not need to practice. A review that leans on the other ten gets far more work done in the same five minutes.
Strong characters still come back, just rarely. A letter you have not heard for a month can surprise you, and a letter that was solid at 12 WPM can wobble at 18. Spaced repetition keeps a light hand on everything and a heavy hand on what is weak right now.
What counts as a miss
In Morse, right but slow is a miss. Grade each character three ways:
| Result | Grade | What happens next |
|---|---|---|
| Named the instant it ended | Strong | Wait longer before the next review |
| Right, but after a pause | Weak | Review again soon |
| Wrong or blank | Missed | Back to daily review |
The middle row is the one people skip, and it is the one that matters most for speed. At 20 WPM the gap between characters is 180 ms. A character you need half a second to recognize is fine at a slow speed and likely to become a miss at a fast one, because the next character has already started.
When you miss, write down what you put instead. Missing V and writing U is a different problem from missing V and writing 4. Confusions often come in pairs, U ..- with V ...-, V with 4 ....-, D -.. with B -..., and a pair is best reviewed together. Morse letters that sound alike lists the usual ones.
For sending, a misshapen character is a miss as well: a dah that came out as a dit, or a pause that split one letter into two.
Doing it by hand: three boxes
You need three envelopes or three columns in a notebook, a card or slip for each character with the letter on the front and its code on the back, and a source of Morse by ear: a friend who sends, a trainer that lets you choose which characters it sends, or recordings you make yourself. It is the same box method many people use for vocabulary cards.
| Box | When you review it | A character moves here when |
|---|---|---|
| 1 | Every session | It is new, or you missed it anywhere |
| 2 | Every other day | It was strong in Box 1 on two separate days |
| 3 | Once a week | It was strong in Box 2 on two reviews in a row |
The rules for moving between boxes:
- A miss in any box sends the character back to Box 1.
- A weak result moves it down one box, not all the way.
- Two strong results in a row move it up one box.
- Keep Box 1 manageable. If it grows longer than you can get through in a few minutes, stop adding new ones until it shrinks.
A session goes in order: Box 1 every time, then Box 2 if it is due, then Box 3 if it is due. Mix two or three strong characters into Box 1 so you are never just choosing between your weakest letters.
For receiving without a partner, record yourself. Shuffle the Box 1 cards, send each one on a key, or by tapping a pencil on the desk, into any voice recorder on your phone or Mac, and copy the recording the next day once you have forgotten the order. That gives you random practice drawn from your own list.
For sending, shuffle the cards, look at the letter on the front, and send it. Only turn the card over to check. Never study from the dots and dashes on the back: the code belongs in your ear and your hand, and the back is only the answer key.
How it fits with learning new characters
Spaced repetition decides which known characters to review. It does not decide when to learn a new one. The Koch method answers that: add a new character when you copy the ones you have at about 90 percent. The Koch method, explained covers it in full.
The two work together. A new character starts life in Box 1, because it is new. The characters you already have keep moving up and down the boxes as you go. When Box 1 is short and your copying is steady, it is time for the next new one.
Two cautions. Keep the speed the same while you grade, because changing speed changes what “strong” means; if you raise the speed, expect a few characters to drop a box, and let them. And review sound, not spelling: the point is recognizing -... as B in one beat, not recalling that B is “a dah and three dits”.
Letting a Mac keep the schedule
The weak point of the box system is the bookkeeping. Dot & Dash does it for you in its daily review, in Practice: “Five minutes on what needs it most.” It brings back the characters that need it most for you to key, so characters you key well come back less often and the ones you miss come back sooner. Its Progress view shows your accuracy on each character, so you can see what the review is working on. The daily review is keyed, so for the ear side, add a few minutes of its Listening drill, where the machine sends and you type what you hear.
Questions
How often should I review Morse characters?
New and missed characters every session; characters you name instantly less and less often, from every other day to once a week. Any miss sends a character back to daily review.
Is spaced repetition a replacement for the Koch method?
No, they answer different questions. The Koch method decides when to add a new character, at about 90 percent copy, and spaced repetition decides which of the characters you already have need review.
Can I use flashcards for Morse code?
Yes, if the front shows only the letter and you answer with sound: send it, tap it or say its rhythm, then check the back. Cards that show dots and dashes on the front train you to read a chart, which is a different skill from hearing Morse.
Does a slow but correct answer really count as a miss?
Treat it as weak and review it soon. At higher speeds the next character starts within a fraction of a second, so recognition that needs a pause will turn into a miss as you speed up.