effet du nombre des graphèmes en Anglais - Aix Marseille Université

240Appendice Iteractive processes operating between orthographic and phonological representations, and that the presentMROM-P provides a viable "model-system" within which such effects can be understood at sufficient levelsof clarity/transparency and formality/precision.Feedback consi stentFeedback i nconsi stent1M R OM1M R OM - P0. 80. 80. 50. 50. 20. 21 1 a( ms) ( ms) (ms)000 10 20 30 400 10 20 30 40Cy cl esCy cl esStone et al . ( 1 9 9 7 )950925900875850F B conF B i nc28M R OM28M R OM - P2727262625251 1 b24F B conF B i nc24F B conF B i ncFigure 11 : Simulation of Stone et al.'s nonword data.MODEL EVALUATIONIn this section, we follow the tentative criteria for model comparison and evaluation proposed in Jacobsand Grainger (1994), in particular : i) potential and actual descriptive accuracy, ii) horizontal and verticalgenerality, and iii) simplicity and falsifiability.POTENTIAL AND ACTUAL DESCRIPTIVE ACCURACY. The first aspect of this accuracy criterion ispotential descriptive accuracy . The question here is : Does the model allow predictions at the level of scale atwhich the dependent variables of interest are actually measured. For example, if the dependent variable thatreflects the effect is interval-scaled (e.g., a frequency effect measured in ms), then a model has potential descriptiveaccuracy if it allows predictions on the scale of ms. Any current psychological A-type model canonly achieve this in an indirect way, for example, by transforming cycle times into RTs via regressionanalyses.Despite complex considerations concerning measurement problems, we think that A-type modelersshould take this issue seriously and provide a means by which model users can formally compare the valuesof the dependent variable(s) they want to study with those of the model's output. This is necessary to developstandards for evaluating the relative goodness-of-fit for competing models. Why should "eye balling"or "hand waving" be accepted as alternatives to model-to-data fitting when using complex A-type models,while they are not accepted for any other formal model format? Massaro and Friedman (1990) provide an encouragingexample for evaluating the descriptive accuracy of a set of comparable M- and A-type models,