Accuracy of Approximate String Joins Using Grams
Bibliographic record
Abstract
Approximate join is an important part of many data cleaning and integration methodologies. Various similarity measures have been proposed for accurate and efficient matching of string attributes. The accuracy of the similarity measures highly depends on the characteristics of the data such as amount and type of the errors and length of the strings. Recently, there has been an increasing interest in using methods based on q-grams (substrings of length q) made out of the strings, mainly due to their high efficiency. In this work, we evaluate the accuracy of the similarity measures used in these methodologies. We present an overview of several similarity measures based on q-grams. We then thoroughly compare their accuracy on several datasets with different characteristics. Since the efficiency of approximate joins depend on the similarity threshold they use, we study how the value of the threshold (including values used in recent performance studies) effects the accuracy of the join. We also compare different measures based on the highest accuracy they can gain on different datasets.
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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 | 0.020 | 0.109 |
| Meta-epidemiology (narrow) | 0.001 | 0.001 |
| Meta-epidemiology (broad) | 0.003 | 0.001 |
| Bibliometrics | 0.005 | 0.008 |
| Science and technology studies | 0.001 | 0.001 |
| Scholarly communication | 0.005 | 0.007 |
| Open science | 0.002 | 0.003 |
| Research integrity | 0.002 | 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".