From: Accumulation of wear and tear in archival and library collections. Part II: an epidemiological study
Exposure variable | Outcome variable: failed sheets (%) | n | 95% CI for mean difference | t | df | p | ||
---|---|---|---|---|---|---|---|---|
M | SD | SE | ||||||
(A) Portfolio | 21.9 | 21.2 | 2.2 | 94 | − 8.6, 6.8 | − 0.24 | 155 | 0.812 |
Box | 22.9 | 30.2 | 3.2 | 88 | ||||
(B) Portfolio (> 100 sheets) | 25.2 | 17.1 | 2.5 | 46 | 1.3, 15.5 | 2.37 | 88 | 0.020 |
Box (> 100 sheets) | 17.7 | 16.8 | 2.5 | 45 |