# Most-cited Mathematics papers of 2018, with free PDFs

The 25 most-cited Mathematics research papers published in 2018, ranked by citations in OpenAlex, with their original abstracts and free PDFs where available.

1. [Advanced Bayesian Multilevel Modeling with the R Package brms](https://nerdi.pages.dev/paper/W2766160192) · 3,038 citations · Free PDF
2. [An Introduction to Statistical Learning: with Applications in R](https://nerdi.pages.dev/paper/W1492815834) · 2,937 citations
3. [A brief introduction to mixed effects modelling and multi-model inference in ecology](https://nerdi.pages.dev/paper/W2783564415) · 2,080 citations
4. [Artificial intelligence and statistics](https://nerdi.pages.dev/paper/W2963819344) · 1,993 citations
5. [Nonlinear Potential Theory of Degenerate Elliptic Equations](https://nerdi.pages.dev/paper/W1544375930) · 1,765 citations
6. [Variable selection – A review and recommendations for the practicing statistician](https://nerdi.pages.dev/paper/W2782176193) · 1,645 citations
7. [Randomised controlled trials – the gold standard for effectiveness research](https://nerdi.pages.dev/paper/W2809266094) · 1,596 citations
8. [Equivalence Testing for Psychological Research: A Tutorial](https://nerdi.pages.dev/paper/W2788930055) · 1,576 citations
9. [Biomarker definitions and their applications](https://nerdi.pages.dev/paper/W2789662105) · 1,532 citations
10. [Designing Difference in Difference Studies: Best Practices for Public Health Policy Research](https://nerdi.pages.dev/paper/W2783319287) · 1,474 citations
11. [Power Analysis and Effect Size in Mixed Effects Models: A Tutorial](https://nerdi.pages.dev/paper/W2783948250) · 1,439 citations
12. [Quasi-Experimental Shift-Share Research Designs](https://nerdi.pages.dev/paper/W2807611776) · 1,425 citations · Free PDF
13. [Minimum sample size for developing a multivariable prediction model: PART II ‐ binary and time‐to‐event outcomes](https://nerdi.pages.dev/paper/W2898559532) · 1,332 citations
14. [Understanding the Lomb–Scargle Periodogram](https://nerdi.pages.dev/paper/W2780156044) · 1,252 citations · Free PDF
15. [The Gaussian Graphical Model in Cross-Sectional and Time-Series Data](https://nerdi.pages.dev/paper/W2795897604) · 1,187 citations · Free PDF
16. [Lack of group-to-individual generalizability is a threat to human subjects research](https://nerdi.pages.dev/paper/W2808831456) · 1,131 citations
17. [Statistical software for analyzing the health effects of multiple concurrent exposures via Bayesian kernel machine regression](https://nerdi.pages.dev/paper/W2888209655) · 1,091 citations · Free PDF
18. [Fixed and random effects models: making an informed choice](https://nerdi.pages.dev/paper/W2886443073) · 1,085 citations · Free PDF
19. [What is the proper way to apply the multiple comparison test?](https://nerdi.pages.dev/paper/W2889216614) · 1,066 citations
20. [Factors associated with clinical trials that fail and opportunities for improving the likelihood of success: A review](https://nerdi.pages.dev/paper/W2885447570) · 1,035 citations
21. [High-Dimensional Probability: An Introduction with Applications in Data Science](https://nerdi.pages.dev/paper/W2787248994) · 1,027 citations
22. [Thinking Clearly About Correlations and Causation: Graphical Causal Models for Observational Data](https://nerdi.pages.dev/paper/W2776946813) · 1,023 citations
23. [How Much Should We Trust Estimates from Multiplicative Interaction Models? Simple Tools to Improve Empirical Practice](https://nerdi.pages.dev/paper/W3045058852) · 977 citations · Free PDF
24. [LASSO regression](https://nerdi.pages.dev/paper/W4252208101) · 977 citations
25. [R-squared for Bayesian Regression Models](https://nerdi.pages.dev/paper/W2904925972) · 928 citations

Canonical page: https://nerdi.pages.dev/papers/mathematics/most-cited-2018