Improving collaboration between statisticians and sports scientists
We welcome the call of Sainani et al. for greater involvement of statisticians with researchers in sports science. However, effective collaboration requires understanding of context and in sports science research is often exploratory, concerned with small samples or predicated on the need to make practical decisions of relatively low risk. We argue for a collaborative approach that recognises the special needs of sports scientists and end-users of their research.
Where should statistical methods be published?
Sainani et al. suggest that statistical methods should be vetted in statistics or general-interest journals before appearing in discipline-specific journals, implying that statistical methods can be evaluated independently of their context. While the mathematical core of statistics may be invariant among most disciplines, connecting these abstractions to the real world requires theoretical and practical assumptions that often depend on discipline-specific knowledge. Beyond that, there are wide philosophical divides among statisticians of frequentist and Bayesian persuasion. Similarly, we have pragmatic considerations like the degree of uncertainty we can accept when making decisions.
Statistical methods are sometimes developed to answer practical questions to which statisticians are blind. The chemist William Gosset studied the statistics of small sample sizes because he had an interest in barley cultivation arising from his employment as a brewer at Guinness. This work didn’t interest contemporary statisticians, who almost always worked with large samples. Similarly, Ronald Fisher developed analysis of variance in the Journal of Agricultural Science and the method was presented side-by-side with the results of its application[3–5]. Few of the new algorithmic approaches that dominate data science were published in statistical journals but rather were developed by computer scientists tackling real-world problems like speech recognition.
Magnitude-based inference (MBI) is presented by Sainani et al. as an example of why new methods should not be published in discipline-specific journals. Yet the procedure was developed to address discipline-specific challenges. Criticisms that statisticians have levied against MBI make no reference to the context in which it is being applied[7,8]. Equally, statisticians' modelling of the method has been incomplete and uses assumptions that are not always valid. If publication of the method in sports science journals had engendered a supportive collaboration, then a long-standing and unhelpful dispute would have been avoided. Instead, statisticians have tended to take an uncompromising stance on MBI that fails to engage thoughtfully with arguments in support of the method[10,11].
Should statistical debate be privileged?
Sainani et al. present several studies as cases supporting their contention that research quality can suffer when statisticians are not involved. They define a statistician as someone from a "methodologically-oriented" academic department, but most of the supposedly unsound studies include authors who by any reasonable definition are experienced applied statisticians. In any case, who qualifies as a statistician should be moot, as science is an open society. One of Robert Merton’s norms of scientific behaviour is universalism – ideas should be judged on their merits alone without reference to their originator. Despite this, some of Sainani et al.’s arguments are calls to authority rather than genuine engagement in scholarly debate. Thus, an alternative approach to principal component analysis, disseminated only as a preprint, is described as flawed because it “does not interpret the data conventionally, interprets the resulting scores as loadings, and has been criticised by an expert in the field”. Preprints are used to solicit feedback prior to journal submission – they are an open invitation to collaborate. Rather than accept this invitation, Sainani et al. publicly castigate the work using two appeals to tradition and a reference to a Twitter conversation.
Collaboration will fail if any party grants themselves the authority to decide truth, especially when there is still debate within the literature. Sainani et al. suggest that sports scientists have overlooked statisticians’ guidelines on response heterogeneity, but do not cite reviews on this topic by exercise scientists[14–16] and by exercise scientists collaborating with a statistician. Similarly, meta-analytical and replicated crossover studies by sports scientists[18–20] (informed by statisticians[21–23]) are not cited. Sainani’s criticism of Loenneke and Dankel refers to non-peer reviewed simulations by Tenan et al.[25,26] (one of Sainani’s co-authors) without considering a rebuttal of those simulations. Moreover, Tenan proclaims an intent to write to the editor of any journal that publishes work using the method to notify them that it is incorrect. This is akin to what Gieryn called ‘boundary work’ – ideological activity that circumvents normal scientific discourse.
Statistics is not a unique, higher value skill. Rather, researchers have a range of specialised knowledge and skills (e.g., coding, research design, experimental skill). Deficiencies in any of these areas can lead to flawed research. Science is error-correcting through the organised scepticism of the scientific community (another of Merton’s norms), not through imposing barriers to participation.
Sports scientists and statisticians have different criteria for what makes a method appropriate, and statistical or mathematical concerns don’t automatically trump experimental, philosophical or practical considerations. Instead, effective collaborations involve consensus-building in a spirit of mutual respect. To progress the field effectively, we need genuine partnerships not authoritarian edicts.
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