[R] clustering levels using Tukey HSD in a one way anova

[Ashim Kapoor]

Dear all,

I am doing a one way between subjects anova in an unbalanced data set.
Suppose we have "a" levels of the one factor. I want to merge the not so
significantly different  levels into the same cluster.

Can I do a Tukey Kramer HSD and then use the following algorithm:

For i in 2 : "a"
     For j in 1 : i-1
            if mean of level i is not significantly different to the mean
of level j,then put i and j in the same cluster. After the first time mean
of level i is not different to the mean of level j , just goto the next i ,
no need to compare with remaining j's.

Alternately,

I do not do Tukey Kramer HSD.  I only run the above algorithm. At each
iteration of the inner loop compute the contrast : mean of level i  = mean
j. At the first match I come out of the inner loop. To control for the (at
most)  1+ 2 + ... + (n-1) comparisons we can use bonferroni/scheffe / some
other technique.

Since this is a statistics query I have posted on stackexchange.  I have
not received a reply so I am posting my query here. Can some one please
answer my query here or on stackexchange?

The link to the query on stackexchange is:

https://stats.stackexchange.com/questions/320930/one-way-
anova-clustering-levels-using-tukey-kramer-hsd

Best Regards,
Ashim

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