Related Experiment Video
Updated: Nov 10, 2025

Development of an Individual-Tree Basal Area Increment Model using a Linear Mixed-Effects Approach
Published on: July 3, 2020
An introduction to new robust linear and monotonic correlation coefficients
Mohammad Tabatabai1, Stephanie Bailey2, Zoran Bursac3
1Meharry Medical College, Nashville, TN, 37208, USA. mtabatabai@mmc.edu.
New robust correlation measures (Taba, TabWil, TabWil rank) offer competitive alternatives to traditional methods, especially with outliers. TBL2 gene expression changes may aid in diagnosing Williams Syndrome.
Area of Science:
- Statistics
- Genomics
- Biostatistics
Background:
- Pearson correlation is standard but sensitive to outliers.
- Robust statistical measures are needed for accurate association analysis.
- Introduces three novel robust correlation estimators: Taba (T), TabWil (TW), and TabWil rank (TWR).
Purpose of the Study:
- To introduce and evaluate new robust correlation measures.
- To compare the performance of T, TW, and TWR against existing classical and robust methods.
- To identify genes associated with Williams Syndrome using Taba distance.
Main Methods:
- Simulation studies to assess robustness and performance (RMSE, bias).
- Comparison with Pearson (P), Spearman (S), Quadrant (Q), Median (M), and Minimum Covariance Determinant (MCD).
- Application of Taba distance and statistical tests for gene association analysis in Williams Syndrome.
Main Results:
- Proposed measures (T, TW, TWR) are competitive with classical (P, S) and robust (Q, M, MCD) methods.
- TBL2 identified as the most significant gene in Williams Syndrome patients, showing reduced expression (P value = 6.37E-05).
Conclusions:
- TWR and T perform best for bias and RMSE, respectively, under specific bivariate distributions (Log-Normal, Weibull).
- MCD shows good performance under Normal distribution; other methods are comparable.
- TBL2 gene expression may serve as a diagnostic marker for Williams Syndrome.
- A Taba R package is available for implementing the proposed methods.
Related Concept Videos
Calculating and Interpreting the Linear Correlation Coefficient
Correlation and Regression
Calibration Curves: Correlation Coefficient
Coefficient of Correlation
If you suspect a linear relationship between x and y, then r can measure how strong the linear relationship is.
What the VALUE of r tells us:
The value of r is always between –1 and +1: –1 ≤ r ≤ 1.
The size of the correlation r indicates the...
Correlation
Two variables, for example, a and b, are said to be positively correlated if both variables move in the same direction. In other words, a positive correlation exists between two variables, a and b, if:
Spearman's Rank Correlation Test
Spearman's test calculates correlation by...

