Performs House nonparametric equivalent of William's test for contrasting increasing dose levels of a treatment in a complete randomized block design.
frdHouseTest(y,...)## Default S3 method:frdHouseTest(y, groups, blocks, alternative = c("greater","less"),...)
Arguments
y: a numeric vector of data values, or a list of numeric data vectors.
groups: a vector or factor object giving the group for the corresponding elements of "x". Ignored with a warning if "x" is a list.
blocks: a vector or factor object giving the block for the corresponding elements of "x". Ignored with a warning if "x" is a list.
alternative: the alternative hypothesis. Defaults to greater.
``: further arguments to be passed to or from methods.
Returns
A list with class "PMCMR" containing the following components:
method: a character string indicating what type of test was performed.
data.name: a character string giving the name(s) of the data.
statistic: lower-triangle matrix of the estimated quantiles of the pairwise test statistics.
p.value: lower-triangle matrix of the p-values for the pairwise tests.
alternative: a character string describing the alternative hypothesis.
p.adjust.method: a character string describing the method for p-value adjustment.
model: a data frame of the input data.
dist: a string that denotes the test distribution.
Details
House test is a non-parametric step-down trend test for testing several treatment levels with a zero control. Let there be k groups including the control and let the zero dose level be indicated with i=0 and the highest dose level with i=m, then the following m = k - 1 hypotheses are tested:
Let Yij(1≤i≤n,0≤j≤k) be a i.i.d. random variable of at least ordinal scale. Further, let Rˉ0,Rˉ1,…,Rˉk
be Friedman's average ranks and set Rˉ0∗,≤…≤Rˉk∗
to be its isotonic regression estimators under the order restriction θ0≤…≤θk.
The statistics is
Tj=(Rˉj∗−Rˉ0)[(Vj−Hj)(2/n)]−1/2(1≤j≤k),
with
Vj=(j+1)(j+2)/12
and
Hj=(t3−t)/(12jn),
where t is the number of tied ranks.
The critical ti,v,α′-values as given in the tables of Williams (1972) for α=0.05 (one-sided) are looked up according to the degree of freedoms (v=∞) and the order number of the dose level (j).
For the comparison of the first dose level (j=1) with the control, the critical z-value from the standard normal distribution is used (Normal).
Examples
## Sachs, 1997, p. 675## Six persons (block) received six different diuretics## (A to F, treatment).## The responses are the Na-concentration (mval)## in the urine measured 2 hours after each treatment.## Assume A is the control. y <- matrix(c(3.88,5.64,5.76,4.25,5.91,4.33,30.58,30.14,16.92,23.19,26.74,10.91,25.24,33.52,25.45,18.85,20.45,26.67,4.44,7.94,4.04,4.4,4.23,4.36,29.41,30.72,32.92,28.23,23.35,12,38.87,33.12,39.15,28.06,38.23,26.65),nrow=6, ncol=6, dimnames=list(1:6, LETTERS[1:6]))## Global Friedman test friedmanTest(y)## Demsar's many-one test summary(frdManyOneDemsarTest(y=y, p.adjust ="bonferroni", alternative ="greater"))## Exact many-one test summary(frdManyOneExactTest(y=y, p.adjust ="bonferroni", alternative ="greater"))## Nemenyi's many-one test summary(frdManyOneNemenyiTest(y=y, alternative ="greater"))## House test frdHouseTest(y, alternative ="greater")
References
Chen, Y.-I., 1999. Rank-Based Tests for Dose Finding in Nonmonotonic Dose–Response Settings. Biometrics 55 , 1258--1262. tools:::Rd_expr_doi("10.1111/j.0006-341X.1999.01258.x")
House, D.E., 1986. A Nonparametric Version of Williams’ Test for Randomized Block Design. Biometrics 42 , 187--190.