Format

Send to

Choose Destination
Med Sci Sports Exerc. 2015 Apr;47(4):874-84. doi: 10.1249/MSS.0000000000000451.

"Magnitude-based inference": a statistical review.

Author information

1
1Mathematical Sciences Institute, Australian National University, Canberra, Australian Capital Territory, AUSTRALIA; and 2Performance Research, Australian Institute of Sport, Belconnen, Australian Capital Territory, AUSTRALIA.

Abstract

PURPOSE:

We consider "magnitude-based inference" and its interpretation by examining in detail its use in the problem of comparing two means.

METHODS:

We extract from the spreadsheets, which are provided to users of the analysis (http://www.sportsci.org/), a precise description of how "magnitude-based inference" is implemented. We compare the implemented version of the method with general descriptions of it and interpret the method in familiar statistical terms.

RESULTS AND CONCLUSIONS:

We show that "magnitude-based inference" is not a progressive improvement on modern statistics. The additional probabilities introduced are not directly related to the confidence interval but, rather, are interpretable either as P values for two different nonstandard tests (for different null hypotheses) or as approximate Bayesian calculations, which also lead to a type of test. We also discuss sample size calculations associated with "magnitude-based inference" and show that the substantial reduction in sample sizes claimed for the method (30% of the sample size obtained from standard frequentist calculations) is not justifiable so the sample size calculations should not be used. Rather than using "magnitude-based inference," a better solution is to be realistic about the limitations of the data and use either confidence intervals or a fully Bayesian analysis.

Comment in

PMID:
25051387
PMCID:
PMC5642352
DOI:
10.1249/MSS.0000000000000451
[Indexed for MEDLINE]
Free PMC Article

Supplemental Content

Full text links

Icon for Wolters Kluwer Icon for PubMed Central
Loading ...
Support Center