Multivariate modeling of missing data within and across assessment waves
Bibliographic record
Abstract
Missing data constitute a common but widely underappreciated problem in both cross-sectional and longitudinal research. Furthermore, both the gravity of the problems associated with missing data and the availability of the applicable solutions are greatly increased by the use of multivariate analysis. The most common approaches to dealing with missing data are reviewed, such as data deletion and data imputation, and their relative merits and limitations are discussed. One particular form of data imputation based on latent variable modeling, which we call Multivariate Imputation, is highlighted as holding great promise for dealing with missing data in the context of multivariate analysis. The recent theoretical extension of latent variable modeling to growth curve analysis also permitted us to extend the same kind of solution to the problem of missing data in longitudinal studies. Data simulations are used to compare the results of multivariate imputation to other common approaches to missing data.
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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 | 0.026 | 0.064 |
| Meta-epidemiology (narrow) | 0.001 | 0.001 |
| Meta-epidemiology (broad) | 0.004 | 0.002 |
| Bibliometrics | 0.004 | 0.009 |
| Science and technology studies | 0.001 | 0.002 |
| Scholarly communication | 0.003 | 0.004 |
| Open science | 0.006 | 0.002 |
| Research integrity | 0.003 | 0.003 |
| Insufficient payload (model declined to judge) | 0.004 | 0.003 |
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".