Cloze deletion flashcards: how to write gaps that work

A cloze deletion card is a sentence with a word or fact hidden, and you have to recall it to fill the gap. It works well when there is a single gap, the sentence gives just enough context for one answer to fit, and the hidden part is something you actually need to remember.

The format is popular because turning a sentence from your notes into a card takes seconds. That speed is also the risk: it is easy to produce dozens of gaps you fill in because the sentence sounds familiar, not because you understand the content. Choosing what to hide is what makes the difference.

Anki has a dedicated note type called Cloze. According to its manual, you mark the text to hide with syntax such as {{c1::ATP}}. Each number creates a separate card: if you write c1 and c2 in the same note, you get two cards, each hiding one part. If you use the same number twice, both parts are hidden together.

The manual also explains how to add a hint inside the gap, for example {{c1::ATP::molecule}}, which shows in place of the usual dots. Use it when a gap allows several reasonable answers and you need to steer without giving the answer away.

Filling a gap without seeing the answer is a form of retrieval practice. Roediger and Karpicke (2006) showed with prose passages that testing yourself led to better recall a week later than restudying the same material. A good cloze card uses that effect on a small scale.

The condition is that the gap demands real recall. If the sentence is so familiar that you fill it in on autopilot, or if the hidden word is an article or a connector, the card is not practicing anything useful. The study did not test cloze cards or any app; it supports the general idea of answering before you look.

These cases are our own and show common mistakes. Notice what changes in each fix: the gap moves to the important fact, and the sentence stops allowing several answers.

Start with a sentence you can back up with your source, written in your own words. Then ask which part you would need to recall on an exam: a term, a number, a relationship. That is your gap. If there are two important candidates, make two cards instead of a double gap.

Then check that the sentence does not give the answer away. If the gap follows “the protein called hemo-,” the clue is in the text. If the sentence copies the textbook word for word, test it later in a different order or wording to see whether you remember the fact or just the sentence.

Gaps suit terms, dates, short formulas and vocabulary in context. They are weaker for long processes, comparisons and explanations. “How do mitosis and meiosis differ in the chromosome number of the daughter cells?” asks you to connect ideas; a gap would tend to shrink it to a single word.

A good rule is to use a gap for what can be said in a few words and a direct question for what you need to explain. Mixing both kinds in one deck is normal and usually gives a more complete review.

Lumia AI does not have a cloze note type like Anki. You can write the sentence with the gap on the front, for example “The Treaty of Versailles was signed in ____,” put the answer on the back and add an optional hint when the gap allows several options. During review you rate the card Again, Hard, Good or Easy.

If you generate a quiz from your book, you can choose the Fill in the Blank question type alongside other formats. Check the generated questions: an ambiguous gap or a wrong answer should be fixed before you practice, just like with your own cards.