Measuring working memory capacity in children using adaptive tasks: Example validation of an adaptive complex span

International audienceWorking memory tasks designed for children usually present trials in order of ascending difficulty, with testing discontinued when the child fails a particular level. Unfortunately, this procedure comes with a number of issues, such as limited psychometric qualities for working memory scores, decreased engagement from high-ability children, and large between-subjects variations in number of trials and testing time. To circumvent these problems, the goal of the present study was to demonstrate the feasibility of assessing working memory in children using an adaptive testing procedure. The principle of adaptive testing is to dynamically adjust the level of difficulty as the task progresses to match the participant's ability. We used this method to develop an adaptive complex span task (the ACCES) comprising verbal and visuo-spatial subtests. The task presents a fixed number of trials to all participants, allows for partial credit scoring and can be used with children regardless of ability level. The ACCES demonstrated satisfying psychometric properties in a sample of 268 children aged 8 to 13 years, confirming the feasibility of using adaptive tasks to measure working memory capacity in children. A free-to-use implementation of the ACCES is provided

Ceramic technology: how to recognize clay processing

The issue of clay processing concerns both provenance and techno-functional ceramic investigations. In the former, the compositional/textural modification of clay alters the petrofacies expressed by the ceramic body and causes a change from the raw material in terms of bulk chemical and mineralogical composition and petrographical features as well. In the latter, identifying the signs of clay processing will provide information on the steps of the chaîne opératoire and on the technological choices made to adjust paste plasticity and to avoid failures in the following stages of manufacture. Several examples of clay processing were considered, encompassing deliberate addition of natural and artificial temper and clay mixing, other than fractioning and homogenisation to prepare the forming stage. The expected effects ofmineral, vegetal and animal tempers on the paste and on the fired body were outlined. Finally, some analytical guidelines are provided to identify clay processing, using the most common analytical methods. Optical microscopy and electron microscopy provide the main contribution to identifying most of the processing practices on the clay, whereas bulk methods provide indirect evidence that may alone be insufficient to prove the occurrence of a specific transformation, as well as to detect homogenisation features. However, only a careful and multidisciplinary investigation of the ceramic body will help reveal the actions of the chaîne opératoire and to test archaeologicalmodels in a sound bottom-up perspective