K | R Documentation |
Jacobsen et al. (2002) sent nine "identical" soil samples to eight soil testing laboratories in the Great Plains region of the Central United States over a three year period of time. Among other characteristics the labs were paid to measure soil potassium. A question of interest was whether the labs would produce identical analytical results.
data(K)
A data frame with 72 observations on the following 2 variables.
K
Soil K in mg/kg
lab
Laboratories, a factor with levels B
D
E
F
G
H
I
J
Jacobsen, J. S., Lorber, S. H., Schaff, B. E., and C. A. Jones (2002) Variation in soil fertility test results from selected Northern Great Plains laboratories. Commun. Soil Sci. plant Anal., 33(3&4): 303-319.
Add the following code to your website.
For more information on customizing the embed code, read Embedding Snippets.