Statistical EOF analysis of spatiotemporal glacier mass-balance variability: a case study of Mittivakkat Gletscher, SE Greenland

An Empirical Orthogonal Function (EOF) variance analysis was performed to map in detail the spatiotemporal variability in individual stake mass-balances (ba) on Mittivakkat Gletscher (MG) – in a region where at present five out of ~20.000 glaciers have mass-balance observations. The EOF analysis suggested that observed ba was summarized by two modes: EOF1 and EOF2 represented 80% (significant) and 6% (insignificant) of the explained variance, respectively. EOF1 captured a decline in ba that was uniformly distributed in space at all stakes. The decline was correlated with albedo observations and air temperature observations from nearby stations. EOF2, however, described variations in ba that were heterogeneously distributed among stakes and associated with local slope and aspect. Low elevation stakes (~<400 m a.s.l.) showed relatively negative (out of phase) correlation and higher elevated stakes relatively positive (in phase) eigenvector correlation values with EOF2. Such relatively negative and positive eigenvector correlation values were present where the constituted of exposed glacier ice or snow cover, respectively. The results from this study show how EOF analyses can provide information on spatiotemporal patterns of glacier mass-balance. Understanding such detailed variabilities in mass-balance on a Greenlandic glacier is of interest because a fifth of the Arctic contribution from glaciers and ice caps to sea-level rise originates from Greenland

Orthographic facilitation in oral vocabulary acquisition

An experiment investigated whether exposure to orthography facilitates oral vocabulary learning. A total of 58 typically developing children aged 8-9 years were taught 12 nonwords. Children were trained to associate novel phonological forms with pictures of novel objects. Pictures were used as referents to represent novel word meanings. For half of the nonwords children were additionally exposed to orthography, although they were not alerted to its presence, nor were they instructed to use it. After this training phase a nonword-picture matching posttest was used to assess learning of nonword meaning, and a spelling posttest was used to assess learning of nonword orthography. Children showed robust learning for novel spelling patterns after incidental exposure to orthography. Further, we observed stronger learning for nonword-referent pairings trained with orthography. The degree of orthographic facilitation observed in posttests was related to children's reading levels, with more advanced readers showing more benefit from the presence of orthography

Some improved diagnostics for failure of the Rasch model

logistic latent trait model, Rasch assumptions, exploration of model fit,

Two new test statistics for the rasch model

unidimensionality axiom,

Psychiatric, business, and psychological applications of fundamental measurement models

This chapter is a collection of four studies applying probabilistic models to problems outside of education. Denmark's Allerup, Bech, and Loldrup present the calibration of the Visual Analogue Scale, used for measuring pain, and the use of this scale for measuring the reductions in pain brought about via the administration of three different treatments. Alvarez and Bañegil's study is a calibration of the criteria by which implementation of Just In Time and Total Quality Management techniques are recognized in Spain. Styles tests the assertion of sociologist O.D. Duncan that the reason for low correlations between measures of attitude and behaviour may be because these variables may not involve separate constructs but simply differing amounts of the same construct. Her conjoint measurement study of data from an Australian survey shows just how much harder it is to do than to say. Finally, from Israel, Tenenbaum presents the results of two studies involving the relationship of anxiety to performance among athletes, showing that commonly used instruments do not produce data of the consistency needed for fit to probabilistic conjoint measurement models in these applications