Rafael Jesús Martínez Cervantes

Generalized eta squared for multiple comparisons on between-groups designs

BACKGROUND Psychological and educational researchers are experiencing many practical difficulties in following the guidelines of the American Psychological Association (APA) for their statistical analyses: one such difficulty is the reporting of an effect-size measure along with each test of statistical significance (APA, 2010). The problem is exacerbated when researchers focus on contrast analysis instead of omnibus tests and when the Type-I error rate per comparison has to be adjusted. METHOD Several reasons for this problem are discussed, with emphasis on the facts that researchers may be presented with too many optional effect-size measures with varying degrees of adequacy in several designs, and common statistical packages fail to provide appropriate effect-size measures for contrast analysis. RESULTS This study proposes specific procedures (also implemented in spreadsheets) to compute generalized eta squared for various kinds of hypotheses, either general or specific, for one-factor and factorial between-group designs, and with manipulated and/or measured factors. CONCLUSIONS Finally, conclusions are drawn concerning the need to take into account the kind of design and the kind of hypothesis in order to calculate comparable effect-size indexes across different types of studies and to prevent an overestimation of effect size.

Desarrollo y estudio piloto de un cuestionario para evaluar la satisfacción con la estancia hospitalaria en población infanto-juvenil

OBJECTIVE To develop an instrument to assess the satisfaction of children and teenagers with their stay in hospital. METHODS A qualitative analysis of hospitalisation satisfaction dimensions based on the feedback of hospitalised children and teenagers; a content validation study by a group of experts of the items generated for the different satisfaction dimensions; and a pilot study to assess the usefulness of the questionnaire with a sample of 84 children and teenagers hospitalised in Andalusia. RESULTS After successive refinements, a short questionnaire was obtained which took between 5 and 15minutes to complete. All items presented positive item-total correlations (r>0.18). The questionnaire showed an internal consistency index of 0.779 (Cronbachs alpha) and significant rank differences (Mann-Whitney U test; p<0.001) with medium size effects (η2>0.151) in three satisfaction dimensions compared between hospitals. DISCUSSION A short, easy-to-answer questionnaire was developed that is reliable regarding its internal consistency and sensitive to differences in hospital satisfaction dimensions. Once validated, it will be used to assess the satisfaction of children and teenagers with their hospital stay, in addition to being a potential indicator of quality of care.