Fill-in-the-blank questions, sometimes called completion or cloze items, look simple. Take a sentence, remove a word, done. That is exactly why so many of them test the wrong thing: whether students remember a sentence from the textbook, not whether they understand the idea behind it.
Written well, they are a strong recall tool. Because students must produce the answer instead of picking it from a list, they practice the harder kind of retrieval. In a 2007 study, Sean Kang, Kathleen McDermott and Henry Roediger found that practicing with short-answer questions, which also require producing an answer, led to better final test performance than multiple-choice practice when students got feedback.
Eight rules for better blanks
1. Blank the key idea, not a filler word
Weak: "Photosynthesis takes place ____ the chloroplasts."
Better: "Photosynthesis takes place in the ____ of plant cells." The blank should be the concept you want students to know.
2. One blank per sentence, usually
"The ____ of a ____ is equal to ____ times ____" is a guessing game. Two blanks can work when they are clearly separate ideas; more than that and the sentence loses its meaning.
3. Put the blank near the end
Students should read the whole idea before they reach the gap. "The process plants use to turn light into chemical energy is called ____" is easier to process than a sentence that opens with a blank.
4. Make sure only one answer fits
"George Washington was born in ____" accepts a year, a state, a colony or a county. Narrow it: "George Washington was born in the year ____." If several answers are reasonable, either accept them all or rewrite the sentence.
5. Do not copy textbook sentences
A sentence lifted straight from the book rewards students who memorized wording. Paraphrase it, or put the idea into a new example: "Ice cubes shrinking in a drink left out on the counter is an example of ____."
6. Avoid grammar clues
"An ____ is a word that describes a noun" gives away a vowel. Use "a(n)" or rephrase. Watch for singular and plural clues too.
7. Keep blanks the same length
If the blank for a long word is longer than the blank for a short one, students will use the length as a hint.
8. Use a word bank when recall is not the goal
For younger students, or when you want to test understanding rather than spelling, add a word bank with a few extra words. Extra options stop students from simply filling the last blank by elimination.
Before and after
| Before | After |
|---|---|
| The ____ is the powerhouse of the cell. | The cell structure that releases energy from glucose is the ____. |
| In 1492, ____ sailed across the ____. | The explorer whose 1492 voyage reached the Caribbean was ____. |
| A ____ angle is ____ than 90 degrees. | An angle that measures less than 90 degrees is called a(n) ____ angle. |
Where fill-in-the-blank fits
Use these questions for key terms, definitions, formulas and short facts that students should be able to produce from memory. For telling similar ideas apart, multiple choice often works better; for explaining reasons, use open-ended questions. A mix of types in one quiz gives you a fuller picture, as we describe in our post on Bloom's taxonomy question stems.
Marking
Decide before marking how strict you will be about spelling and synonyms. For a science term, "chloroplast" spelled "cloroplast" probably shows the knowledge you wanted; for a spelling test it does not. Tell students the rule in advance.
If you want a quick first draft, the fill-in-the-blank generator turns your notes, slides or a PDF into blanks with an answer key, on every plan. Then apply the rules above as you review them.
Summary
- Blank the idea that matters, near the end of the sentence.
- Make sure exactly one answer fits, and remove grammar and length clues.
- Paraphrase instead of copying the textbook.
