Measurement and statistics: An examination of construct validity.

Uses principles of latent trait theory to derive conditions under which mean differences on an observed variable are indicative of mean differences on an underlying construct, focusing on the logistic curve as a model for describing the relation between the observed variable and construct. In this situation, and with normally distributed scores on the construct, a t test comparing groups on the observed variable produces correct inferences at the construct level only if group variances on the construct are homogeneous or the difficulty level of the test equals the mean ability level of the examinees. (27 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

ModerateDrinking.Com and moderation management: Outcomes of a randomized clinical trial with non-dependent problem drinkers.

Objective: To evaluate the effectiveness of a web-based protocol, ModerateDrinking.com (MD; www.moderatedrinking.com) combined with use of the online resources of Moderation Management (MM; www.moderation.org) as opposed to the use of the online resources of MM alone. Method: We randomly assigned 80 problem drinkers to either the experimental or control group with follow-ups at 3, 6, and 12 months. Results: Seventy-five participants (94%) had outcome data at 1 or more follow-up points, and 59 participants (73%) were assessed at all 3 follow-ups. Comparing baseline measures to the average outcomes at follow-ups indicated a significant overall reduction in both groups in alcohol-related problems and consumption variables. Compared with the control group, the experimental group had better outcomes on percent days abstinent. There was an interaction between intensity of drinking at baseline and treatment in determining outcomes assessing drinking. Less heavy drinkers in the experimental group had better outcomes on log mean blood alcohol content (BAC) per drinking day compared with the control group. Heavier drinkers did not differentially benefit from the MD program on this measure. Mixed model analyses in general corroborated these outcomes. Conclusion: The outcome data provide partial evidence for the effectiveness of the MD web application combined with MM, compared with the effectiveness of the resources available online at MM by themselves. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Formation of stable Langmuir-Blodgett multilayers from oxiran carboxylic acids

Long-chain carboxylic acids, having oxiran groups at various positions along the chain, were synthesized and tested for their capacity to form ordered monolayers and multilayers. The oxiran groups were included because of their potential for polymerization during electron beam lithography. The hydrophilic nature of both the carboxylic acid and the oxiran groups in the same molecule afforded some difficulties in film formation, but one of these compounds provided stable monolayers and multilayers. Initial investigations have revealed that these multilayers are sensitive to electron beam polymerization.     

Seafloor temperature and conductivity data from Stefansson Sound, Alaska

Overconsolidated sediments, seasonal seafloor freezing, and ice-bonded permafrost are unique features in shallow arctic coastal waters. They are related to low seawater temperatures and varying salinities. Seabed temperatures can be less than −1.0°C for much of the year, with noticeable warming occurring only during the summer months. Observations from recent deployment of three instruments in Stefansson Sound and data from an earlier deployment, which included sites in Harrison Bay, showed decreasing mean annual seafloor temperatures with increasing water depth, ranging from −0.9°C in 4.4 m of water to −1.6°C in 14 m of water. Salinities also varied seasonally, with noticeable freshening developing during the summer and highly uniform values occurring during the winter. Periodic temperature and salinity measurements at sites in Stefansson Sound, made during August 1987 and August 1989, also helped verify the data obtained with the seabottom instruments.Seasonal freezing of the seabed can begin in late September and may noticeably change its engineering properties. In areas of coarse-grained sediments, ice bonding and strengthening of the seabed can result. In areas of fine-grained sediments it appears that seasonal freezing of the seafloor can cause overconsolidation of the seabed sediments. This densification process can result in a significant permanent increase in strength.     

The test-retest reliability of the Form 90-DWI: An instrument for assessing intoxicated driving.

Although driving while intoxicated (DWI) is a pervasive problem, reliable measures of this behavior have been elusive. In the present study, the Form 90, a widely utilized alcohol and substance use instrument, was adapted for measurement of DWI and related behaviors. Levels of reliability for the adapted instrument, the Form 90-DWI, were tested among a university sample of 60 undergraduate students who had consumed alcohol during the past 90 days. The authors administered the instrument once during an intake interview and again, 7-30 days later, to determine levels of test-retest reliability. Overall, the Form 90-DWI demonstrated high levels of reliability for many general drinking and DWI behaviors. Levels of reliability were lower for riding with an intoxicated driver and for variables involving several behavioral conjunctions, such as seat belt use and the presence of passengers when driving with a blood alcohol concentration above .08. Overall, the Form 90-DWI shows promise as a reliable measure of DWI behavior in research on treatment outcome and prevention. (PsycINFO Database Record (c) 2010 APA, all rights reserved)