Chunking Chapters - By The Numbers

I recently outlined my rationale for chunking textbook chapters into smaller bits. In the article Reducing Text Anxiety, I explain that breaking large chapters into smaller chapters improves reading comprehension.  Learning experts call this "reducing cognitive load" and both expert and poor readers benefit by shorter chapters. Now let's look at the numbers behind this chunking.

Comparison to the Previous Edition

As the first table shows, the average chapter length of the new edition of Anatomy & Physiology has dropped by a whopping 23% without changing the length of the textbook.  Likewise, the longest chapter in the book is now 19% shorter than the longest chapter in the previous edition.

	A&P/8e	A&P/9e	Difference
Total (chapters)	37	48	+11
Total (pages)	1140	1140	same
Average (pages/chapter)	30.8	23.8	- 23%
Shortest chapter (pages)	16	12	-25%
Longest chapter (pages	52	43	-19%

Comparison to Other A&P Textbooks

The second table compares a few other 2-semester A&P textbooks to the new edition of our Anatomy & Physiology.  At an average chapter length of only 24 pages, our chapters are about 12 pages (33%) shorter than the nearest compared textbook.  And our chapters are 19 pages (44%) shorter than the compared textbook with the longest chapter average.

Again, our Anatomy & Physiology has 33-44% shorter chapters compared to other A&P textbooks of comparable length and coverage.

Textbook	Chapter Count	Page Count	Average Pages / Chapter
Seeley 10e	29	1248	43.0
McKinley 1e	29	1169	40.3
Saladin 6e	29	1136	39.2
Tortora 14e	29	1127	38.9
Hole 13e	24	925	38.5
Martini 9e	29	1114	38.4
Marieb (big) 9e	29	1107	38.2
Marieb (little) 5e	26	923	35.5
Patton 9e	48	1140	23.8

As an expert reader myself, I would much rather be tackling a technical textbook that is chunked into smaller, more digestible chapters. I can only imagine how much more helpful such chunking will be for readers who:

• struggle with reading
• have too many distractions in their lives
• are challenged with learning in English
• are underprepared
• have learning disabilities