| Title: |
Necessary but not Sufficient: Limitations of Projection Quality Metrics |
| Authors: |
Machado, A.; Behrisch, M.; Telea, A.; Sub Visualisation and Graphics |
| Publication Year: |
2025 |
| Subject Terms: |
CCS Concepts; • Computing methodologies → Machine learning; • Human-centered computing → Information visualization; • Mathematics of computing → Dimensionality reduction; Computer Graphics and Computer-Aided Design |
| Description: |
High-dimensional data analysis often uses dimensionality reduction (DR, also called projection) to map data patterns to human-digestible visual patterns in a 2D scatterplot. Yet, DR methods may fail to show true data patterns and/or create visual patterns that do not represent any data patterns. Projection Quality Metrics (PQMs) are used as objective measures to gauge the above process: the higher a projection's scores in PQMs, the more it is deemed faithful to the data it represents. We show that, while PQMs can be used as exclusion criteria — low values usually mean poor projections — the converse does not always hold. For this, we develop a technique to automatically generate projections that score similar or even higher PQM values than projections created by well-known techniques, but show different, often confusing, visual patterns. Our results show that accepted PQMs cannot be used as an exclusive way to tell whether a projection yields accurate and interpretable visual patterns — in this sense, PQMs play a role akin to that of summary statistics in exploratory data analysis. We also show that not all studied metrics can befooled equally well, suggesting a ranking of metrics in their ability to reliably capture quality. |
| Document Type: |
article in journal/newspaper |
| File Description: |
application/pdf |
| Language: |
English |
| ISSN: |
0167-7055 |
| Relation: |
https://dspace.library.uu.nl/handle/1874/477044 |
| Availability: |
https://dspace.library.uu.nl/handle/1874/477044 |
| Rights: |
info:eu-repo/semantics/OpenAccess |
| Accession Number: |
edsbas.75BF89D6 |
| Database: |
BASE |