Invariance Properties for General Diagnostic Classification Models

In item response theory (IRT), the invariance property states that item parameter estimates are independent of the examinee sample, and examinee ability estimates are independent of the test items. While this property has long been established and understood by the measurement community for IRT models, the same cannot be said for diagnostic classification models (DCMs). DCMs are a newer class of psychometric models that are designed to classify examinees according to levels of categorical latent traits. We examined the invariance property for general DCMs using the log-linear cognitive diagnosis model (LCDM) framework. We conducted a simulation study to examine the degree to which theoretical invariance of LCDM classifications and item parameter estimates can be observed under various sample and test characteristics. Results illustrated that LCDM classifications and item parameter estimates show clear invariance when adequate model data fit is present. To demonstrate the implications of this important property, we conducted additional analyses to show that using pre-calibrated tests to classify examinees provided consistent classifications across calibration samples with varying mastery profile distributions and across tests with varying difficulties.     

Perceptions of Overt and Personality-based Integrity Tests

Differences in test-taker perceptions between overt and personality-based integrity tests were examined. Following administration of both types of integrity tests, 255 undergraduate students provided ratings of perceived face validity and perceived predictive validity. Following receipt of actual test scores, 126 test takers participated in a second phase of the study in which they reported perceptions of distributive justice. Test takers perceived overt integrity tests as having greater face validity and predictive validity than personality-based integrity tests. Perceptions of job-relatedness were not strongly related to test performance on either test type. Distributive justice perceptions were related to test performance, but not type of integrity test.     

Parent vs. Self-Report: Contributions Toward Diagnosis of Adolescent Psychopathology

Assessment of psychopathology in adolescents can be complicated due to uncertainties about who should be considered the primary informant. While a multimethod, multiinformant approach to assessment allows for a thorough assessment, it can also result in contradictory findings. The purpose of this study was to use a sample of 121 adolescents to investigate issues of parent-adolescent agreement on behavior rating scales and a structured diagnostic interview. Additionally, this study evaluated whether adolescent report offers unique information to the assessment beyond the parent's report. The sample included both normal controls and adolescents who met criteria for diagnosis of an Internalizing or Externalizing disorder based on the DSM-IV criteria. Agreement between parents and adolescents on the Diagnostic Interview for Children and Adolescents—Revised (DICA-R) was low for ADHD (39.4%) and Externalizing Disorders (41.1%) and moderate for Internalizing Disorders (56.6%). A significant difference was found between the number of ADHD symptoms reported, with parents reporting more symptoms (M = 9.42) than adolescents (M = 8.34). Regression analysis indicated that the adolescent completed Youth Self-report (YSR) contributed unique information beyond the parent completed measures in predicting both the adolescent and the parent interviews for Internalizing Disorders. This finding emphasizes the need to continue to collect self-report information, especially when assessing Internalizing disorders, which inherently contain symptoms indicating high-risk behaviors such as suicide ideation.     

Positive reinforcement of litter removal in the natural environment

Litter is an especially large and costly problem in unsupervised high-use recreational areas. This study investigated procedures to induce visitors to remove litter from an unsupervised U.S. Forest Service area in which signs attached to two litter stations instructed people to pick up and deposit litter. A small sum of money or chances on a larger sum given for participation usually resulted in more bags of litter being picked up per week. Although only a small proportion of the area's users participated in the project, ground surveys indicated the areas sampled were somewhat freer of litter during the payment condition. The results suggest that small monetary rewards may be a promising approach to litter control in unsupervised as well as supervised areas.     

Reliability and validity of the Group Embedded Figures Test for a grade school sample.

Data on validity of the Group Embedded Figures Test for 22 sixth grade students (9 boys and 13 girls) were obtained. 50 wk. later all subjects were individually screened on the Portable Rod-and-Frame Test and after a period of 2 more weeks, when they were retested on the embedded figures, data on reliability were obtained. Long-term coefficients of stability of .80 and .71 for the 9 boys and 13 girls, respectively, were obtained. Coefficients of internal consistency ranged from .83 to .98 for boys and girls. Coefficients reflecting both construct and concurrent validity were -.60 and .00 for boys and girls, respectively. Customary sex differences with respect to field-dependence--independence were not observed for these small samples.     

The role of crowding in parallel search: Peripheral pooling is not responsible for logarithmic efficiency in parallel search

Recent results from our laboratory showed that, in fixed-target parallel search tasks, reaction times increase in a logarithmic fashion with set size, and the slope of this logarithmic function is modulated by lure-target similarity. These results were interpreted as being consistent with a processing architecture where early vision (stage one) processes elements in the display in exhaustive fashion with unlimited capacity and with a limitation in resolution. Here, we evaluate the contribution of crowding to our recent logarithmic search slope findings, considering the possibility that peripheral pooling of features (as observed in crowding) may be responsible for logarithmic efficiency. Factors known to affect the strength of crowding were varied, specifically: item spacing and similarity. The results from three experiments converge on the same pattern of results: reaction times increased logarithmically with set size and were modulated by lure-target similarity even when crowding was minimized within displays through an inter-item spacing manipulation. Furthermore, we found logarithmic search efficiencies were overall improved in displays where crowding was minimized compared to displays where crowding was possible. The findings from these three experiments suggest logarithmic efficiency in efficient search is not the result peripheral pooling of features. That said, the presence of crowding does tend to reduce search efficiency, even in “pop-out” search situations.