Using Interleaving to Build Lasting Spelling Skills in Your Classroom

Every elementary/early middle school teacher, and parent, has experienced it: students master the spelling list for the Friday test, only for those words and patterns to vanish from their working memory soon after. Rote memorization might yield short-term results, but how do we foster spelling skills that stick and transfer into students’ independent writing?

The answer might lie in embracing a strategy that, counterintuitively, makes practice feel harder: interleaving. As educator and author Carl Hendrick recently discussed while citing new research, there’s a core truth we often overlook: learning should feel hard. Easy practice often equates to superficial learning. Interleaving embodies this principle, known as a “desirable difficulty.”

Let’s unpack what interleaving is, why the cognitive effort it demands is beneficial for spelling, and how you can leverage this evidence-based strategy using Spelling Test Buddy.

What is Interleaving? (Hint: It’s Not Blocking)

Interleaving simply means mixing up different but related skills or concepts within a single practice session.

It stands in contrast to blocking, the more traditional method where students practice one skill or type of problem repeatedly before moving on.

• Blocking Example: Practicing only ch words, then only tch words.
• Interleaving Example: Practicing a mix of ch and tch words together (e.g., much, match, witch, rich, catch, teach).

Why does interleaving often feel more challenging for students (and sometimes, teachers)? Because it disrupts the illusion of fluency that comes with blocked practice. Interleaving demands more cognitive work:

• Active Retrieval: Students can’t just stay in one “groove.” They must constantly pull different patterns or rules from memory.
• Discrimination: They are forced to compare and contrast related concepts, identifying the subtle differences that determine which pattern applies (Is it ch or tch here? Why?).
• Selection: They must choose and apply the correct strategy for each specific word.

This increased mental effort is the “desirable difficulty.” It’s not difficulty for difficulty’s sake; it’s the kind of effortful processing that leads to deeper understanding, stronger memory traces, and more flexible knowledge. As Hendrick emphasizes, the struggle during effective practice isn’t a sign of failure; it’s often the sign of meaningful learning happening.

Why Harder Is Better: The Science Behind Interleaving for Spelling

The benefits of interleaving aren’t just theoretical. A recent classroom-based study, Using interleaved practice to foster spelling acquisition (Klimovich and Richter, 2025) provides compelling evidence for its effectiveness in spelling acquisition with third graders:

1. Improved Accuracy: Students practicing spelling rules with an interleaved schedule showed better immediate accuracy compared to blocked practice.
2. Lasting Retention: The benefits were durable. Eight weeks later, students who learned through interleaving still demonstrated superior recall of the practiced spelling patterns.
3. Crucial Transfer: This is where interleaving truly shines for educators. The interleaved group was significantly better at spelling new, previously unseen words that followed the practiced rules. This indicates they weren’t just memorizing words; they were internalizing and learning to apply the spelling patterns.
4. Effective Consolidation: While beneficial overall, the long-term gains were most pronounced for students who already had an average or better grasp of spelling concepts, suggesting interleaving is particularly powerful for consolidating and deepening understanding.
5. Confirms “Desirable Difficulty”: The study perfectly illustrated Hendrick’s point. Students perceived interleaved practice as harder and were less confident immediately afterward. However, their actual long-term learning and ability to transfer the knowledge were significantly better. This disconnect between perceived ease and actual learning effectiveness is crucial for teachers to recognize.

This research underscores that the cognitive effort demanded by interleaving helps students build a more robust and flexible understanding of spelling rules, enabling them to retain knowledge longer and apply it correctly in new contexts – exactly what we aim for in our instruction.

Implementing Interleaving with Spelling Test Buddy in Your Classroom

Spelling Test Buddy offers a flexible platform to integrate interleaving into your classroom and home spelling test instructional routines:

1. Identify Related but Confusable Patterns: Based on your curriculum and student error patterns, group rules or features that are often mixed up (e.g., ie/ei, homophones, suffix addition rules like doubling consonants, hard/soft c/g).
2. Create Mixed Practice Lists: Instead of lists dedicated to a single pattern, build lists in Spelling Test Buddy that strategically combine 2-3 related but distinct patterns. Example: A list could include words with ai, ay, and a_e.
3. Integrate Cumulative Review: Apply interleaving to review. Create lists mixing current focus patterns with words from previous weeks that exemplify different, potentially confusable patterns. This reinforces discrimination over time.
4. Leverage Spelling Test Buddy Features:
   • Assign formal tests using your interleaved lists.
   • Use “Practice Mode” with mixed lists for independent work or centers. The immediate feedback helps students navigate the discrimination process.
   • Utilize the spelling games with interleaved lists for engaging, effortful practice.

Managing the “Desirable Difficulty” in Class

Because interleaving feels harder, it’s important to manage student perception:

• Explain the ‘Why’: As Carl Hendrick advises, tell your students why you’re mixing things up. Explain that feeling challenged is part of building a “stronger spelling brain” and that this type of practice helps information stick better long-term.
• Frame the Struggle Positively: Normalize the initial difficulty. It’s not a sign they “aren’t getting it,” but rather that they are engaging in deep learning.
• Start Small: Begin by interleaving just two similar concepts before increasing complexity.

Elevate Your Spelling Instruction

While blocked practice might offer temporary comfort and apparent fluency, interleaving provides a pathway to more durable, transferable spelling skills. By embracing the “desirable difficulty” of interleaving, you equip students with a deeper understanding of orthographic patterns.

Use Spelling Test Buddy to create targeted, interleaved practice opportunities and help your students build spelling skills that truly last.

Ready to try it? Create your first interleaved spelling list in Spelling Test Buddy this week!