My previous post in this series ended by discussing various techniques for sequencing part-task practice.  Ordinarily, Ten Steps to Complex Learning recommends that you design learning tasks so they have a “high contextual interference.”  In other words, within a class of learning tasks, the individual tasks differ from each other as much as they do in the real world.  The idea is that this helps the learn build mental models and cognitive strategies.

But part-task practice doesn’t need those models and strategies.  So the practice items in a given set resemble each other quite a bit–there’s low contextual interference.  According to van Merriënboer and Kirschner, this helps the learner automate particular recurrent skill being practiced.

Presenting Procedures for Part-task Practice

Step 7 (design procedural information) advocates a whole-task approach toward procedural information.  Part-task practice is by definition procedural, and so much of the advice from Step 7 applies, even though we’re now talking about specific procedural skills for which additional practice makes sense.

Take the complex skill of becoming a chef.  Plenty of non-recurrent skills there, but as Jacques Pépin knows, lots of recurrent ones (procedural skills) as well.

For novice chefs, then, you might demonstrate knife-sharpening or cutting vegetables into julienne strips in a whole-task context.  To  practice how to sharpen or julienne, though, you’d then demonstrate the specific procedure in isolation.

Other instructional methods for difficult aspects of a recurrent task:

• Subgoaling: have the learner describe the goal (the result) reached by a particular process.  (“Now that you’ve sliced the onions…?”)
• Focusing attention: highlight steps that are difficult or dangerous.  (E.g., in a graphic demo, color-code or otherwise emphasize the dangerous steps.)
• Multiple representations: use more than one format to present difficult procedures and rules.  (For example, a real-life demonstration by an expert along with a simulation that the learner can control.)
• Matching: compare and contrast correct demonstrations with incorrect ones.  (Use correct and incorrect examples of carrying [in addition] to show why carrying is necessary.)

Do this?  Don’t do that?  How’m I doing?

vM&K use “continent tutoring” to mean monitoring the learner’s performance and presenting procedural information just-in-time.  Part-task practice is focused on particular skills, and so it’s easier for an instructor or a computer system to provide that JIT knowledge as needed.

Likewise, corrective feedback is easier for part-task practice, because the range of behavior is narrower.  Ten Steps discusses a “model tracing” approach, where the observer or a computer program monitors the learner’s progress on each step or rule.  Suppose the practice item involves solving the math problem:

3 ( 2x + 5 ) = 9

If a step’s correct, there’s no feedback.  If incorrect, feedback could look like this:

• You tell the learner “you’ve made an error.”
• You explain the error.  “You multiplied 2X by 3.  In a problem like this, you also need to multiply the 5 by 3 .”

Practice to overlearn

Part-task practice has two effects: it helps combine small rules into larger chunks (“knowledge compilation”), and it strengthens the application of those rules through deliberate, repeated practice.

vM&K cite the “power law of practice,” another side trip into math ( “the log of the time to complete a response [is] a linear function of the log of the number of successful executions” ).

Here’s the idea.  Let’s say you take 3 seconds to add two digits.  You practice 100 times, and lower the rate to 2 seconds.  Here’s the improvement from further practice:

• 1,000 items gets you to 1.6 seconds
• 10,000 items gets you to 1.3 seconds
• 100,000 items gets you to 1.0 seconds

Key point here: first,  compilation (acquiring basic skill with a procedure or rule) takes much less time than strengthening.  Second, strengthening continues over a long period of time.

I think there’s a connection with the notion that it takes 10,000 hours to become an expert (though I see “10,000 hours” as a metaphor, rather than as a strict standard).  At age 93, Pablo Casals was asked why he continued to practice scales every day, more than 80 years after he began studying the cello.  “Because I think I’m making progress.”

Building skill

Part-task practice typically goes through three stages:

• Accuracy: the goal is to reach an acceptable level of accuracy.  In typing, for example, that might mean typing the letter C and using the correct finger to do so.
• Speed: the learner performs the skill under moderate speed stress, like a typing drill.  The goal is to maintain current accuracy under stress.  One effect is to make it impossible to follow the steps in a procedure consciously (“move the middle finger of the left hand down to the C key, then press”), forcing automatic.
• Integration: the learner performs the skill along with related skills, still striving to maintain speed and accuracy.  An example would be moving from typing drills (“cog cog cog tic tic tic can can can”) to full text.

Some skills can’t sensibly be practiced sufficiently in real time to develop automaticity.  Simulations can compress such time.  Ten Steps gives an example of air-traffic controllers.  Usually there’s a gap of about 5 minute between telling an aircraft to where to turn and seeing the result on a monitor.  A simulation can compress that to a few seconds, and the novice air-traffic controller “can practice more items on one day than in one year of normal training.”

Part-task practice seems to work better when it’s distributed–relatively short periods of practice, spaced over time–than when it’s done in long, concentrated periods of drill.  In addition, alternating practice sessions with other learning activities, according to vM&K, helps make the practice more effective.

Making practice work (in a good sense)

The Ten Steps emphasizes two principles for part-task practice:

• Learners must be able to related the practice to whole-task performance.
• Part-task practice should be distributed, and should alternate with learning tasks.

vM&K cite a study in which college students were learning Boolean functions.  Practice with 8,000 items before the whole task (troubleshooting logical circuits) had no effect; practice had a positive effect after exposure to a simple version of the whole task.

…And with that, I’m done with the details of the Ten Steps. Two remaining chapters deal with media and with self-directed learning; a final one has the title, “Closing Remarks.”  So the series isn’t quite done, but I think eventually it will be.

CC-licensed images: chef-knife photo by Sara Björk;
addition problems by Arenamontanus;
USAF air traffic controller by Lietmotiv.

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