calcium2: Calcium pot trial with alternative representation

In smbdata: Data from "Statistical Methods in Biology"

Calcium pot trial with alternative representation

Description

In this experiment, four relative concentrations of calcium (A = 1, B = 5, C = 10, D = 20) were each applied to five individual plants, with treatments assigned in a completely randomized design across 20 pots. After the experimental period, the total root length (in centimeters) of each plant was measured. The resulting dataset includes both the root length measurements and a set of dummy variables representing the levels of the Calcium treatment factor. This structure facilitates statistical analysis of the effects of different calcium concentrations on plant root growth.

Usage

calcium2

Format

A data frame with 7 variables: Pot, Calcium, Length, d1, d2, d3, d4.

Pot

Factor. Unique identifier for each pot (experimental unit).

Calcium

Factor. Calcium treatment group for each pot, with levels "A" = 1, "B" = 5, "C" = 10, "D" = 20.

Length

Integer. Total root length (in centimeters) measured for each pot at the end of the experiment.

d1

Integer. Dummy variable indicating membership in calcium level "A" (1 if Calcium = "A", 0 otherwise).

d2

Integer. Dummy variable indicating membership in calcium level "B" (1 if Calcium = "B", 0 otherwise).

d3

Integer. Dummy variable indicating membership in calcium level "C" (1 if Calcium = "C", 0 otherwise).

d4

Integer. Dummy variable indicating membership in calcium level "D" (1 if Calcium = "D", 0 otherwise).

Source

Welham, S. J., Gezan, S. A., Clark, S. J., and Mead, A. (2015) Statistical Methods in Biology: Design and analysis of experiments and regression

Examples

anova(lm(Length ~ 1 + d2 + d3 + d4, data = calcium2))

smbdata documentation built on Jan. 20, 2026, 5:06 p.m.