This document discusses setting objectives for library collections. It provides examples of using actuarial science concepts like average life expectancy, population size, and items added per time period to determine a stable collection size and items circulated. The document presents examples of calculating the collection size, average weeding age, and annual items added. It also discusses using average days in loan periods and turnaround times to estimate items out and items to be shelved. Finally, it presents exercises for setting multiple objectives for a collection.
7. Expectation of Life
for a stable population
Average Life Expectancy
Entrants per Time Unit
Population Size
Entrants per Time Unit
Population Size
Average Life Expectancy
Population Size Average Life Expectancy Entrants per Time Unit
Average Life Expectancy
Entrants per Time Unit
Population Size
Entrants per Time Unit
700
10
70
Population Size
700
10
Average Life Expectancy 70
Population Size Average Life Expectancy Entrants per Time Unit
70 10 700
8. Weeding Age, Collection Size, and Items Added
Average Weeding Age
Annual Items Added
Collection Size
Annual Items Added
Collection Size
Average Weeding Age
Collection Size Average Weeding Age Annual Items Added
Average Weeding Age
Annual Items Added
Collection Size
Annual Items Added
Collection Size
Average Weeding Age
700
10
70
700
10
70
Collection Size Average Weeding Age Annual Items Added 10 70 700
9. Other Expectation of Life Applications
Average Days in Loan Period
Average Shelving TurnaroundTime
Average Items Out
Average Daily Circulation
Average Items To Be Shelved
Average Daily Circulation
Average Interlibrary Loan TurnaroundTime
Average Items in Request File
Average Loans per Day
10. Policy Assumptions for Rhizome
Objectives
•
•
•
•
•
Median age
Collection size
Steady-state snapshots
Annual iterations
Supply-Demand Equality
19. “Unto every one that
hath shall be
given, and he shall
have abundance; but
from him that hath not
shall be taken away
even that which he
hath.”
— Matthew 25:29