Linked Questions

73
votes
6answers
40k views

Choosing a clustering method

When using cluster analysis on a data set to group similar cases, one needs to choose among a large number of clustering methods and measures of distance. Sometimes, one choice might influence the ...
35
votes
3answers
21k views

How to select a clustering method? How to validate a cluster solution (to warrant the method choice)?

One of the biggest issue with cluster analysis is that we may happen to have to derive different conclusion when base on different clustering methods used (including different linkage methods in ...
33
votes
2answers
46k views

Choosing the right linkage method for hierarchical clustering

I am performing hierarchical clustering on data I've gathered and processed from the reddit data dump on Google BigQuery. My process is the following: Get the latest 1000 posts in /r/politics ...
25
votes
3answers
83k views

How to interpret the dendrogram of a hierarchical cluster analysis

Consider the R example below: plot( hclust(dist(USArrests), "ave") ) What exactly does the y-axis "Height" mean? Looking at North Carolina and California (...
18
votes
4answers
19k views

How to understand the drawbacks of Hierarchical Clustering?

Can someone explain the pros and cons of Hierarchical Clustering? Does Hierarchical Clustering have the same drawbacks as K means? What are the advantages of Hierarchical Clustering over K means? ...
16
votes
3answers
29k views

What algorithm does ward.D in hclust() implement if it is not Ward's criterion?

The one used by option "ward.D" (equivalent to the only Ward option "ward" in R versions <= 3.0.3) does not implement Ward's (1963) clustering criterion, whereas option "ward.D2" implements ...
4
votes
1answer
24k views

Hierarchical or TwoStep cluster analysis for binary data?

(This question is an edited version of a question I previously posted which one user recommended would benefit from more focus). I have 2000 questionnaires from respondents which ask 33 different ...
1
vote
3answers
5k views

Ask for suggestions on clustering methods on a large dataset with mixed types of variables

I need to build segmentation on a large customer dataset with more than 300K records and many variables, including continuous like income and age, ordinal like education level and membership level, ...
6
votes
3answers
1k views

Can sub-optimality of various hierarchical clustering methods be assessed or ranked?

Classic agglomerative hierarchical clustering methods are based on a greedy algorithm. This means that they (many of them) are prone to give sub-optimal solutions instead of the global optimum result, ...
3
votes
2answers
1k views

Compare two hierarchical trees

I want to measure the similarity between two hierarchical trees generated from the same n objects. The two trees are generated using the same metric at two different instants. Thus, I would like to ...
4
votes
2answers
580 views

Which unsupervised classification method to use next if hierarchical clustering gave bad results?

Purposes I need to perform a classification of weather stations taking into account the characteristics of intra-annual variability of some two climate indicators. There are 613 sites with monthly ...
1
vote
0answers
3k views

Which hierarchical cluster method and measure to use for binary data?

I have a dataset with only ordinal binary variables (asymmetric categories: present vs absent). I have read about the (dis)simmilarity measures for binary data, but not about the clustering method (e....
3
votes
0answers
3k views

A high cophenetic correlation coefficient but dendrogram seems bad

I have 2 results for the same dataset. One is hierarchical clustering using Ward's method and I got 0.75 cophenetic correlation coefficient. The second is average method and I got 0.91 cophenetic ...
3
votes
0answers
3k views

Gower's dissimilarity measure and Ward's clustering method

I have read some threads on this website saying that it is not OK to use Gower's dissimilarity matrix for Ward's clustering algorithm. I have mixed type variables, first I had a dissimilarity matrix ...
5
votes
1answer
924 views

Purpose of dendrogram and hierarchical clustering

This is likely a very naive question. I've lately been reading about hierarchical clustering algorithms, and various discussions about how to interpret dendrograms or find optimal heights for cutting ...

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