Learning by generating vs. receiving instructional explanations: Two approaches to enhance attention cueing in animations

This study investigated whether learners construct more accurate mental representations from animations when instructional explanations are provided via narration than when learners attempt to infer functional relations from the animation through self-explaining. Also effects of attention guidance by means of cueing are investigated. Psychology students were given retention, inference, and transfer tests after studying a cued or an uncued animation of the cardiovascular system with learner-generated self-explanations or with externally provided instructional explanations. Results indicated that cued animations were more effective than uncued animations. Furthermore, results on retention and transfer indicated no differences between self-explaining and providing instructional explanations, but instructional explanations accompanying animations led to higher inference scores. It is concluded that whether explanations are generated or presented may be less important than the provision of cues that enable focused processing of presented or produced explanations.     

Wallace E. Lambert (1922–2009).

On August 23, 2009, psychology lost an innovative researcher with the passing, at 86, of Wallace E. Lambert. A professor of psychology at McGill University from 1954 until 1990, Wallace (“Wally”) Lambert was among the founders of psycholinguistics and sociolinguistics. His highly productive career included contributions to social and cross-cultural psychology (intergroup attitudes, child-rearing values, and psychological consequences of living in multicultural societies), language education (the French immersion program), and bilingualism (measurement of language dominance, attitudes and motivation in second-language learning, and social, cognitive, and neuropsychological consequences of bilingualism). Indeed, because of the scope and influence of his work, Wally Lambert is widely considered the father of the psychological study of bilingualism. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Posttraumatic stress disorder patients' readiness to change alcohol and anger problems.

Notes that recovery from combat-related posttraumatic stress disorder (PTSD) is often complicated by unacknowledged problems with alcohol and anger. 102 males combat veterans (aged 42–63 yrs) entering a residential PTSD rehabilitation program completed University of Rhode Island Change Assessment and process-of-change questionnaires based on J. O. Prochaska and C. C. DiClemente's transtheoretical model (TTM; J. O. Prochaska et al, 1992). Separate assessments were made for alcohol abuse and anger control. Four motivational subtypes were identified for both problems. Motivation to change alcohol problems was independent of that for anger. Relative to less-motivated peers highly motivated patients were more like to spontaneously identify alcohol or anger as problems in their life and made greater use of change strategies specified by the TTM. These results support extension of the TTM to anger management and to PTSD management. Treatment implications are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Performance of submillimeter square hollow waveguides

Propagation losses are determined for 100 microm x 100 microm square, hollow waveguides constructed from glass capillaries. The small size makes it possible to observe optical effects not easily seen with larger waveguides. The depletion of higher-order even modes creates a large, nonlinear loss. Over a distance of a meter the loss approaches the smaller, linear value expected for the fundamental mode. Additionally, the lowest two even modes beat to produce an oscillatory loss with a period of approximately 2 cm. Making the focal radius 0.35 the waveguide width minimizes these two effects. In a related study, 50-microm waveguides embossed in polydimethylsiloxane are shown to have losses similar to glass capillaries.     

Characterization of milk properties with a radiative transfer model

To characterize milk through light-scattering measurements, a semianalytical radiative transfer model was used to simulate the backscatter of light in milk having homogenized fat levels from 0.05 to 3.2 wt. %. The input parameters to the model include the incident wavelength, refractive index of particles and medium, and particle number densities. By varying the wavelength, we can obtain a reasonable fit between experimental data and the model for lower fat milks. Results indicate that the model is most sensitive to the particle diameter and size distribution and less sensitive to the number and index of refraction of the particles.     

Characterization of seasonal variation of forest canopy in a temperate deciduous broadleaf forest, using daily MODIS data

In this paper, we present an improved procedure for collecting no or little atmosphere- and snow-contaminated observations from the Moderate Resolution Imaging Spectroradiometer (MODIS) sensor. The resultant time series of daily MODIS data of a temperate deciduous broadleaf forest (the Bartlett Experimental Forest) in 2004 show strong seasonal dynamics of surface reflectance of green, near infrared and shortwave infrared bands, and clearly delineate leaf phenology and length of plant growing season. We also estimate the fractions of photosynthetically active radiation (PAR) absorbed by vegetation canopy (FAPAR_canopy), leaf (FAPAR_leaf), and chlorophyll (FAPAR_chl), respectively, using a coupled leaf-canopy radiative transfer model (PROSAIL-2) and daily MODIS data. The Markov Chain Monte Carlo (MCMC) method (the Metropolis algorithm) is used for model inversion, which provides probability distributions of the retrieved variables. A two-step procedure is used to estimate the fractions of absorbed PAR: (1) to retrieve biophysical and biochemical variables from MODIS images using the PROSAIL-2 model; and (2) to calculate the fractions with the estimated model variables from the first step. Inversion and forward simulations of the PROSAIL-2 model are carried out for the temperate deciduous broadleaf forest during day of year (DOY) 184 to 201 in 2005. The reproduced reflectance values from the PROSAIL-2 model agree well with the observed MODIS reflectance for the five spectral bands (green, red, NIR₁, NIR₂, and SWIR₁). The estimated leaf area index, leaf dry matter, leaf chlorophyll content and FAPAR_canopy values are close to field measurements at the site. The results also showed significant differences between FAPAR_canopy and FAPAR_chl at the site. Our results show that MODIS imagery provides important information on biophysical and biochemical variables at both leaf and canopy levels.     

Modeling the behavior of the 4/5ths rule for determining adverse impact: Reasons for caution.

The Equal Employment Opportunity Commission's 4/5ths rule has been used for over 20 years in applied psychology and employment law. The rule signals that there is adverse impact when the protected group selection ratio is less than 80% of the highest scoring group's selection ratio. We conducted several simulations and found, consistent with some previous management science literature, that the 4/5ths rule often resulted in false-positive readings of adverse impact even when there were no underlying (population) standardized group differences between subgroups. We then incorporated tests of statistical significance and found that adding such tests to the 4/5ths rule eliminated many false-positive indications of adverse impact. We also examined simulated selection systems based on meta-analytic values from the selection literature. The frequency of adverse impact signals from the 4/5ths rule increased markedly relative to simulations with no subgroup population differences. Adding statistical tests mitigated the number of indications of adverse impact to some extent. (PsycINFO Database Record (c) 2010 APA, all rights reserved)