Performance Evaluation of Some Clustering Algorithms under Different Validity Indices
Bibliographic record
Abstract
Clustering, a pivotal technique in statistics, enables the summarisation of data sets through the identification of related object groups.A prevalent question in clustering literature pertains to the precise number of partitions present within a data set.An array of clustering methods and indices has been proposed to discern the optimal number of clusters within a data set, each following its own set of rules.However, none of these methods universally excel in capturing the true components across all types of data structures.Particularly, they tend to grapple with uniquely shaped data sets or instances where objects from different groups are in close proximity.In this study, the performance of several clustering methods (Single Linkage, Complete Linkage, Average Linkage, Centroid Linkage, Ward.2DLinkage, Median Linkage) is evaluated in conjunction with different internal validity indices (KL, CH, Sil, Gap).This evaluation utilises simulated data, encompassing varied models, sample sizes, and distance measures, and is conducted using R software 3.1.Furthermore, several external indices (Rand, F-M, Purity) are employed to ascertain the degree of agreement between the true clusters of data points and the partitions computed through the clustering methods.
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.037 | 0.098 |
| Meta-epidemiology (narrow) | 0.002 | 0.001 |
| Meta-epidemiology (broad) | 0.002 | 0.002 |
| Bibliometrics | 0.009 | 0.006 |
| Science and technology studies | 0.003 | 0.002 |
| Scholarly communication | 0.005 | 0.003 |
| Open science | 0.003 | 0.003 |
| Research integrity | 0.003 | 0.001 |
| Insufficient payload (model declined to judge) | 0.001 | 0.001 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".