Practical Significance: Ordinal Scale Data and Effect Size in Zooarchaeology

Quantitative analysis of zooarchaeological taxonomic abundances and skeletal part frequencies often relies on parametric techniques to test hypotheses. Data upon which such analyses are based are considered by some to be ‘ordinal scale at best’, meaning that non‐parametric approaches may be better suited for addressing hypotheses. An important consideration is that archaeologists do not directly or randomly sample target populations of artefacts and faunal remains, which means that sampling error is not randomly generated. Thus, use of inferential statistics is potentially suspect. A solution to this problem is to rely on a weight of evidence research strategy and to limit analysis to descriptive statistics. Alternatively, if one chooses to use statistical inference, one should analyse effect size to determine practical significance of results and adopt conservative, robust inferential tests that require relatively few assumptions. Archaeologists may choose not to abandon statistical inference, but if so, they should temper how they use statistical tools. Copyright © 2014 John Wiley & Sons, Ltd.