9/20 For more on the specific question of the t-test and robustness to non-normality, I'd recommend looking at this paper by Lumley and colleagues. is also robust against unequal variances. is robust against deviations from normality; the t-test with the unequal-variances s.e. For this example, it is obvious that 60 is a potential outlier. robust statistics, which worries about the properties of . A common exercise in empirical studies is a “robustness check”, where the researcher examines how certain “core” regression coefficient estimates behave when the regression specification is modified by adding or removing regressors. Robustness testing has also been used to describe the process of verifying the robustness (i.e. The papers review the state of the art in statistical robustness and cover topics ranging from robust estimation to the robustness of residual displays and robust smoothing. Some statistics, such as the median, are more resistant to such outliers. More detailed explanations of many test statistics are in the section Statistics explained. writing on robustness in social science statistical journals (e.g., Algina, Keselman, Lix, Wilcox) have promoted the use of trimmed means. Simulations can be used to show the same, but with more questionable generality. One could examine the … For example: Robustness to outliers; Robustness to non-normality Despite the leading place of fully parametric models in classical statistics, elementary This comes at the price of a small loss of power for the case that actually the variances are equal. with the pooled s.e. In econometrics, both problems appear, usually together, and it is useful to refer to th e treatment of both problem s in economic applications as robust econometrics. Robustness in Statistics contains the proceedings of a Workshop on Robustness in Statistics held on April 11-12, 1978, at the Army Research Office in Research Triangle Park, North Carolina. Robustness is a test's resistance to score inflation through whatever cause; practice effects, fraud, answer leakage, increasing quality of research materials … ANSI and IEEE have defined robustness as the degree to which a system or component can function correctly in the presence of invalid inputs or stressful environmental conditions. Addition - 1st May 2017 Robustness has various meanings in statistics, but all imply some resilience to changes in the type of data used. Cite 1 Recommendation In Identifying Outliers and Missing Data we show how to identify potential outliers using a data analysis tool provided in the Real Statistics Resource Pack. Robustness in Statistics contains the proceedings of a Workshop on Robustness in Statistics held on April 11-12, 1978, at the Army Research Office in Research Triangle Park, North Carolina. In the preceding lecture module, we described a single sample test and con dence interval using a trimmed mean. Robustness. The final result will not do, it is very interesting to see whether initial results comply with the later ones as robustness testing intensifies through the paper/study. This may sound a bit ambiguous, but that is because robustness can refer to different kinds of insensitivities to changes. In fact, the median for both samples is 4. correctness) of test cases in a test process. For more on the large sample properties of hypothesis tests, robustness, and power, I would recommend looking at Chapter 3 of Elements of Large-Sample Theory by Lehmann.