For Printed Materials: The Probability of Appearance

Munsell's 1834-40 Printings by Number of Pages and Size of Print Run

Print runs/Number of pages	1 to 16 Pages	17 to 71 Pages	72 + Pages
400 or less Copies	6	11	0
401 to 1000	6	15	4
1,001 to 4,000	3	4	3
4000+	1	1	1

Let's look at statistics comparing the number of pages to the number of copies located in the OCLC. For works of at least 72 pages the survival rate in the OCLC is 1 in 184. Thus if a 1,000 copies were printed and the item had at least 72 pages we can estimate there will be 5 or 6 copies in the OCLC. For material, mostly pamphlets, with 17 to 71 pages the survival rate is 1 in 221, for pamphlets of 16 pages or less 1 in 502. When few copies were printed and the item had 16 pages or less the likelihood of survival is very small. When the print run as well as the number of pages is small we see mass extinction.

Munsell's 1834-40 Printings in the OCLC Analyzed by Number of Pages and Size of Print Run, Divided into Present and Not Present and Expressed as Percentages

Publications & Copies	1 to 16 Pages		17 to 71 Pages		72 + Pages
	present	not present	present	not present	present	not present
400 or less Copies	33%	67%	36%	64%
401 to 1000	28%	72%	63%	37%	80%	20%
1,001 to 4,000	100%	0%	100%	0%	100%	0%
4000+	0%	100%	0%	100%

Both small print run and small page count are strong nagatives for survival. Such material is automatically uncommon although not necessarily important or valuable. Most examples are simply curiosities.