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Blocked vs. Random Practice: Motor Learning for Articulation and Phonology

By the Edgewise team · · 7 min read

Pronunciation

Blocked practice repeats one target many times in a row. Random practice mixes several targets in an unpredictable order. Outside speech, blocked practice looks better during practice, while random practice is usually remembered and transferred better. In speech the evidence is mixed, so the practical plan is: blocked to find a sound, random once it's stable.

These principles come from motor learning and from speech therapy for speech disorders, borrowed here for language learners. Learning a language is not a disorder, and neither is an accent.

What's the difference between blocked and random practice?

Blocked Random
Order perro, perro, perro… pero, pero, pero… pero, carro, perro, caro, perro, pero…
How it feels Smooth, confident Harder, more mistakes
Best for Finding a new sound Keeping it and using it in new words
The risk It feels like learning when it isn't yet Too hard too soon

The idea behind random practice has a name: contextual interference. Switching targets makes practice harder, and that effort seems to help learning stick. The standard review of the effect is by Magill and Hall (1990).

Articulation vs. phonology: which one is this about?

SLPs separate two kinds of speech sound problems. Articulation problems are about motor production: getting the mouth to make the sound. Phonological problems are rule-based patterns that affect a whole class of sounds (ASHA). ASHA also notes that the two are often hard to tell apart.

Language learners have both. A new trill is a motor job. Puffing every Spanish p is an English rule at work (see why your English sound rules follow you).

Practice schedules belong to the motor side. For rule-level patterns, SLPs also use contrast approaches and cycles.

What motor learning research found

Schema theory. Schmidt (1975) proposed a schema theory of motor skill learning. It's commonly summarized this way: you learn a general rule for a family of movements, and varied practice strengthens that rule. Treat it as theory, not a finding.

The classic experiment. In Shea and Morgan (1979), 72 students learned three arm-movement tasks in blocked or random order. The blocked group was much faster early in practice, but by the last block the groups were close. Random practice gave better retention when test conditions changed, and better transfer, especially to the hardest new task.

The challenge point. How much a practice condition helps depends on how hard the task is for you, given your skill. There's an optimal level of challenge (Guadagnoli & Lee, 2004). The framework offers testable ideas, not data. Its message: add difficulty as you improve, not on day one.

What speech studies found

Few studies test these principles in speech, though a major tutorial judged them promising (Maas et al., 2008). The studies that exist are mostly clinical and small.

Who What happened Source
4 adults with apraxia of speech All four combinations of intensity and schedule improved. No clinically meaningful differences at follow-up. Wambaugh et al., 2013
6 adults with apraxia Both schedules worked and generalized to untreated words. Random seemed to hold up better for 2 people. Wambaugh et al., 2014
20 adults with apraxia No significant difference in effect sizes. Random gave larger gains on treated items only. Wambaugh et al., 2017
20 adults with apraxia Change came after about 334 trials (blocked) vs. 179 trials (random). The authors judged the dosage difference not substantial. Wambaugh, Kallhoff & Nessler, 2021
4 children with childhood apraxia 2 did better with blocked, 1 with random, 1 with neither. Maas & Farinella, 2012
80 healthy adults, 40 to 80 Over 59: random helped spatial learning, constant practice helped timing. Younger: no schedule effects. Kaipa, Robb & Jones, 2017

The 2014 authors put it plainly: non-speech findings "may not translate directly" to speech (Wambaugh et al., 2014). The children with apraxia are the clearest warning: when a sound is very hard to make at all, blocked practice may fit better.

Mixing easy and hard

Concurrent Treatment randomly mixes easy and hard tasks instead of climbing from easy to hard. Children aged 4 to 7 with s errors learned the sound quickly and carried it from syllables up to connected speech (Skelton, 2004). A randomized study tested a small-group version with 28 children aged 6 to 9. They acquired their target sounds within 40 half-hour sessions (d = 1.31) (Skelton & Richard, 2016).

Speech motor chaining tunes feedback, variety and difficulty to performance. Most children in it reach more than 200 practice trials per session (Preston, Leece & Storto, 2019).

Many tries

The number of tries matters too. In a study of 2 children with childhood apraxia, 100+ productions in 15 minutes beat 30 to 40. Learning was faster, with more carryover to untrained words (Edeal & Gildersleeve-Neumann, 2011).

Adult language learners

Evidence is thin. Eight Korean adults learning English r did better in the short term when they practiced across many words instead of one. Long-term learning was limited either way (Bu et al., 2021). That study tested variety of words, not blocked vs. random order.

Twelve Korean adult learners of English had 12 weekly sessions with less frequent, slightly delayed feedback. Intelligibility, naturalness and precision improved, and 7 kept their gains at 6 months (Kim et al., 2017). With no control group, we can't credit the method alone.

Don't confuse schedule with target choice

Another SLP finding gets mixed up with this one. In children with phonological delays, choosing more complex targets sparked wider generalization (Gierut, 2007).

That's about what you practice. Blocked vs. random is about how you order your practice. A complex target can be practiced in blocks. A simple one can be practiced in random order. Make the two choices separately.

A practice plan you can use

  1. Find it (blocked). One target word, many tries in a row, with feedback on every try. Stop when you get it right most of the time.
  2. Mix it (random). Shuffle the target with its contrast words. Check every other try.
  3. Stretch it (more variety). Add new words, phrases and speeds. If you're getting almost everything right, it's too easy. If you're missing most, step back.
  4. Use it (connected speech). Retell a short story and listen for your target words.

Example: Spanish tap and trill

Stage What you say
Find it para, para, para… (single tap), then perro, perro, perro… (trill)
Mix it pero, perro, caro, carro, para, rosa in shuffled order
Stretch it El perro corre. (The dog runs.) Pero no es caro. (But it's not expensive.)
Use it A retell, listening for every r

Example: French u vs. ou

Stage What you say
Find it tu, tu, tu… until [y] is steady
Mix it tu, tout, su, sous, rue, roue in shuffled order
Stretch it La tortue court. (The tortoise runs.) C'est tout. (That's all.)
Use it A retell, listening for tortue and court

Example: Korean 불, 뿔, 풀

Stage What you say
Find it 불, 불, 불… (fire), then 뿔 (horn), then 풀 (grass), one block each
Mix it All three in shuffled order, plus 달, 딸, 탈 (moon, daughter, mask)
Stretch it 불이 났어요. (There's a fire.) 풀이 많아요. (There's a lot of grass.) 뿔이 있어요. (It has horns.)
Use it A retell, listening for your target words

Retelling the same story twice is a different kind of repetition, at the level of whole stories.

For teachers, tutors and SLPs

The speech evidence comes from apraxia, childhood apraxia and speech sound disorders, plus two small adult L2 studies. None tests an adult practicing alone. Treat blocked-then-random as a default, and if accuracy collapses in random practice, go back to blocks for a session.

FAQ

Is random practice better than blocked practice? For retention and transfer in non-speech motor skills, usually yes. In speech studies the advantage is small, inconsistent or absent, and some children with apraxia did better with blocked practice.

When should I switch from blocked to random practice? When you can make the sound correctly most of the time in one word. Before that, random practice may just mean more errors.

What is the challenge point framework? It's the idea that the best practice difficulty depends on your current skill. In practice, that means easier conditions early and more variety as you improve.

How many repetitions should I do? Many. In one small study of children with apraxia, 100 or more productions in 15 minutes beat 30 to 40. In speech motor chaining, most children pass 200 trials per session.

Your next step: Drills build the sound. Retells test it. Try a story retell in Edgewise: real connected speech, where your practiced words have to hold up. Edgewise scores story structure and sentence building, not pronunciation, and ends every round with your next piece to add.

Join early access

Related: How to practice pronunciation with motor learning · Why your English sound rules follow you

Sources

  1. American Speech-Language-Hearing Association. (n.d.). Speech sound disorders: Articulation and phonology [Practice Portal]. https://www.asha.org/practice-portal/clinical-topics/articulation-and-phonology/
  2. Bu, L., Nagano, M., Harel, D., & McAllister, T. (2021). Effects of practice variability on second-language speech production training. Folia Phoniatrica et Logopaedica, 73(5), 384–400. https://doi.org/10.1159/000510621
  3. Edeal, D. M., & Gildersleeve-Neumann, C. E. (2011). The importance of production frequency in therapy for childhood apraxia of speech. American Journal of Speech-Language Pathology, 20(2), 95–110. https://doi.org/10.1044/1058-0360(2011/09-0005)
  4. Gierut, J. A. (2007). Phonological complexity and language learnability. American Journal of Speech-Language Pathology, 16(1), 6–17. https://doi.org/10.1044/1058-0360(2007/003)
  5. Guadagnoli, M. A., & Lee, T. D. (2004). Challenge point: A framework for conceptualizing the effects of various practice conditions in motor learning. Journal of Motor Behavior, 36(2), 212–224. https://doi.org/10.3200/JMBR.36.2.212-224
  6. Kaipa, R., Robb, M., & Jones, R. (2017). The effectiveness of constant, variable, random, and blocked practice in speech-motor learning. Journal of Motor Learning and Development, 5(1), 103–125. https://doi.org/10.1123/jmld.2015-0044
  7. Kim, I. S., Kang, H. S., Pirruccello, L., Kweon, S., & Oh, C. (2017). Motor learning theory-based approach for teaching English as a second language. Speech, Language and Hearing, 20(2), 63–70. https://doi.org/10.1080/2050571X.2016.1213561
  8. Maas, E., & Farinella, K. A. (2012). Random versus blocked practice in treatment for childhood apraxia of speech. Journal of Speech, Language, and Hearing Research, 55(2), 561–578. https://doi.org/10.1044/1092-4388(2011/11-0120)
  9. Maas, E., Robin, D. A., Austermann Hula, S. N., Freedman, S. E., Wulf, G., Ballard, K. J., & Schmidt, R. A. (2008). Principles of motor learning in treatment of motor speech disorders. American Journal of Speech-Language Pathology, 17(3), 277–298. https://doi.org/10.1044/1058-0360(2008/025)
  10. Magill, R. A., & Hall, K. G. (1990). A review of the contextual interference effect in motor skill acquisition. Human Movement Science, 9(3–5), 241–289. https://doi.org/10.1016/0167-9457(90)90005-X
  11. Preston, J. L., Leece, M. C., & Storto, J. (2019). Tutorial: Speech motor chaining treatment for school-age children with speech sound disorders. Language, Speech, and Hearing Services in Schools, 50(3), 343–355. https://doi.org/10.1044/2018_LSHSS-18-0081
  12. Schmidt, R. A. (1975). A schema theory of discrete motor skill learning. Psychological Review, 82(4), 225–260. https://doi.org/10.1037/h0076770
  13. Shea, J. B., & Morgan, R. L. (1979). Contextual interference effects on the acquisition, retention, and transfer of a motor skill. Journal of Experimental Psychology: Human Learning and Memory, 5(2), 179–187. https://doi.org/10.1037/0278-7393.5.2.179
  14. Skelton, S. L. (2004). Concurrent task sequencing in single-phoneme phonologic treatment and generalization. Journal of Communication Disorders, 37(2), 131–155. https://doi.org/10.1016/j.jcomdis.2003.08.002
  15. Skelton, S. L., & Richard, J. T. (2016). Application of a motor learning treatment for speech sound disorders in small groups. Perceptual and Motor Skills, 122(3), 840–854. https://doi.org/10.1177/0031512516647693
  16. Wambaugh, J. L., Kallhoff, L., & Nessler, C. (2021). Sound production treatment for acquired apraxia of speech: An examination of dosage in relation to probe performance. American Journal of Speech-Language Pathology, 30(1S), 425–440. https://doi.org/10.1044/2020_AJSLP-19-00110
  17. Wambaugh, J. L., Nessler, C., Cameron, R., & Mauszycki, S. C. (2013). Treatment for acquired apraxia of speech: Examination of treatment intensity and practice schedule. American Journal of Speech-Language Pathology, 22(1), 84–102. https://doi.org/10.1044/1058-0360(2012/12-0025)
  18. Wambaugh, J. L., Nessler, C., Wright, S., & Mauszycki, S. C. (2014). Sound production treatment: Effects of blocked and random practice. American Journal of Speech-Language Pathology, 23(2). https://doi.org/10.1044/2014_AJSLP-13-0072
  19. Wambaugh, J. L., Nessler, C., Wright, S., Mauszycki, S. C., DeLong, C., Berggren, K., & Bailey, D. J. (2017). Effects of blocked and random practice schedule on outcomes of sound production treatment for acquired apraxia of speech: Results of a group investigation. Journal of Speech, Language, and Hearing Research, 60(6S), 1739–1751. https://doi.org/10.1044/2017_JSLHR-S-16-0249

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