Again: Shorter Is Better

Sousa tells us that "another fascinating characteristic of the primacy-recency effect is that the proportion of prime-times to down-time changes with the length of the teaching episode."  Translation:

• In a 40 minute lesson, Prime Time 1 and Prime Time 2 combined total about 30 minutes of 'good learning time' (or 75% of the teaching time vs. 25% of down time.)
• If we double the length of the learning episode to 80 minutes, the down-time increases to 30 minutes, or 38% of the total time period.

As the lesson lengthens, the percentage of down-time increases faster than for the prime-times.

BUT if she shorten the learning time to 20 minutes, the down-time is about 2 minutes, or 10% of the total lesson time.  Therefore, there is a higher probability of effective learning in shorter teaching episodes.

• Four 20 minute episodes have 18min Prime Time x 4 = 72 minutes of effective learning.
• One 80 minute episode has 50 minutes of effective learning.

Therefore, if you have a big block of time to teach, it is best to divide it into smaller chunks.

So, once again, shorter is better :)