Datamining assignment

  
Answer the following questions. Please ensure to use the Author, YYYY APA citations with any content brought into the assignment.  

For      sparse data, discuss why considering only the presence of non-zero values      might give a more accurate view of the objects than considering the actual      magnitudes of values. When would such an approach not be desirable?
Describe      the change in the time complexity of K-means as the number of clusters to      be found increases.
Discuss      the advantages and disadvantages of treating clustering as an optimization      problem. Among other factors, consider efficiency, non-determinism, and      whether an optimization-based approach captures all types of clusterings      that are of interest.
What      is the time and space complexity of fuzzy c-means? Of SOM? How do these complexities      compare to those of K-means?
Explain      the difference between likelihood and probability.
Give      an example of a set of clusters in which merging based on the closeness of      clusters leads to a more natural set of clusters than merging based on the      strength of connection (interconnectedness) of clusters.