morley

Michelson Speed Of Light Data

A pre-loaded example dataset in R

Main page: https://www.rdocumentation.org/packages/datasets/versions/3.6.2/topics/morley

head(morley)

##     Expt Run Speed
## 001    1   1   850
## 002    1   2   740
## 003    1   3   900
## 004    1   4  1070
## 005    1   5   930
## 006    1   6   850

require(stats); require(graphics)
michelson <- transform(morley,
                       Expt = factor(Expt), Run = factor(Run))
xtabs(~ Expt + Run, data = michelson)  # 5 x 20 balanced (two-way)

##     Run
## Expt 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
##    1 1 1 1 1 1 1 1 1 1  1  1  1  1  1  1  1  1  1  1  1
##    2 1 1 1 1 1 1 1 1 1  1  1  1  1  1  1  1  1  1  1  1
##    3 1 1 1 1 1 1 1 1 1  1  1  1  1  1  1  1  1  1  1  1
##    4 1 1 1 1 1 1 1 1 1  1  1  1  1  1  1  1  1  1  1  1
##    5 1 1 1 1 1 1 1 1 1  1  1  1  1  1  1  1  1  1  1  1

plot(Speed ~ Expt, data = michelson,
     main = "Speed of Light Data", xlab = "Experiment No.")

fm <- aov(Speed ~ Run + Expt, data = michelson)
summary(fm)

##             Df Sum Sq Mean Sq F value  Pr(>F)   
## Run         19 113344    5965   1.105 0.36321   
## Expt         4  94514   23629   4.378 0.00307 **
## Residuals   76 410166    5397                   
## ---
## Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1

fm0 <- update(fm, . ~ . - Run)
anova(fm0, fm)

## Analysis of Variance Table
## 
## Model 1: Speed ~ Expt
## Model 2: Speed ~ Run + Expt
##   Res.Df    RSS Df Sum of Sq      F Pr(>F)
## 1     95 523510                           
## 2     76 410166 19    113344 1.1053 0.3632