Psychological symptoms in sexually abused girls

This study examined psychological symptoms exhibited by children who had recently been sexually abused. Twenty-four girls aged 6 to 12 years old were evaluated within six months of being abused using a variety of standardized child psychiatric instruments. Results showed a marked discrepancy between child and parent reports of symptoms. The abused children did not exhibit significant depressive, anxiety, or low self-esteem symptoms by self-report; however, their parents rated them as having significantly more behavioral problems than a normative sample but as somewhat less pathological than a clinical sample. The implications of these findings in relation to our current understanding of the psychological problems manifested by sexually abused children and for future research are discussed.     

Cognitive conflict and intuitive rules

This paper is a part of an extensive project on the role of intuitive rules in science and mathematics education. First, we described the effects of two intuitive rules ‐‐ ‘Everything comes to an end’ and ‘Everything can be divided’ ‐‐ on seventh to twelfth grade students’ responses to successive division tasks related to mathematical and physical objects. Then, we studied the effect of an intervention, which provided students with two contradictory statements, one in line with students’ intuitive response, the other contradicting it, on their responses to various successive division tasks. It was found that this conflict‐based intervention did not improve students’ ability to differentiate between successive division processes related to mathematical objects and those related to material ones. These results reconfirmed that intuitive rules are stable and resistant to change. Finally, this paper raised the need for additional research related to the relationship between intuitive rules and formal knowledge.     

Item Parameter Estimation Under Conditions of Test Speededness: Application of a Mixture Rasch Model With Ordinal Constraints

When tests are administered under fixed time constraints, test performances can be affected by speededness. Among other consequences, speededness can result in inaccurate parameter estimates in item response theory (IRT) models, especially for items located near the end of tests (Oshima, 1994). This article presents an IRT strategy for reducing contamination in item difficulty estimates due to speededness. Ordinal constraints are applied to a mixture Rasch model (Rost, 1990) so as to distinguish two latent classes of examinees: (a) a "speeded" class, comprised of examinees that had insufficient time to adequately answer end-of-test items, and (b) a "nonspeeded" class, comprised of examinees that had sufficient time to answer all items. The parameter estimates obtained for end-of-test items in the nonspeeded class are shown to more accurately approximate their difficulties when the items are administered at earlier locations on a different form of the test. A mixture model can also be used to estimate the class memberships of individual examinees. In this way, it can be determined whether membership in the speeded class is associated with other student characteristics. Results are reported for gender and ethnicity.     

The role of within-trial location of the retention interval in rats’ delayed conditional discrimination performance

Rats were trained and tested on delayed conditional discriminations (DCDs) consisting of four possible light and tone stimulus sequences: light-light, tone-tone, light-tone, and tone-light. A lever was presented after the offset of the second or test stimulus, S₂. Two retention intervals (RIs) were present within the DCD task, one (RI-1) between the sample or first stimulus (S₁) and S₂, and the other (RI-2) between S₂ and presentation of the lever. Liquid reinforcement was contingent upon pressing only when S₂ matched S₁ in Experiment 1 or only when S₂ differed from S₁ in Experiment 2. RI-1 and RI-2 were separately increased to 5,10, and 20 sec from 1-sec training conditions. Increasing RI-1 produced greater declines in performance to light S₁ than to tone S₁ in both experiments. No such stimulus modality effect occurred for increases in RI-2 in these experiments. These results indicate that retrospection of S₁ occurred during RI-1 and prospection of a response decision and reward expectancy primarily occurred during RI-2.