Using Multidimensional Item Response Theory to Evaluate Educational and Psychological Tests

Many educational and psychological tests are inherently multidimensional, meaning these tests measure two or more dimensions or constructs. The purpose of this module is to illustrate how test practitioners and researchers can apply multidimensional item response theory (MIRT) to understand better what their tests are measuring, how accurately the different composites of ability are being assessed, and how this information can be cycled back into the test development process. Procedures for conducting MIRT analyses–from obtaining evidence that the test is multidimensional, to modeling the test as multidimensional, to illustrating the properties of multidimensional items graphically-are described from both a theoretical and a substantive basis. This module also illustrates these procedures using data from a ninth-grade mathematics achievement test. It concludes with a discussion of future directions in MIRT research.     

Documenting the world’s sociological literature:Sociological abstracts

Since its founding in 1953,Sociological Abstracts has abstracted and indexed the worldwide literature of sociology and the related social sciences. Growth and specialization within the field are reflected in the number of publications screened, the addition of new document types, the range of languages covered, and the increased specificity of indexing and classication.     

Evolution of Graduate Education in Electrical Engineering in Metropolitan Areas

The evolution of graduate education in electrical engineering began in the early 1890' s and progressed at a rapid pace in the 1920' s, particularly in metropolitan areas conscious of community needs. In these areas, evening programs held the spotlight because of the ever-demanding need to provide graduate engineers with advanced knowledge. Such cooperation between community interests and colleges has resulted in a wide variety of patterns of part-time study on campus and, more recently, off campus. The later development is viewed with criticism in several educational circles although off-campus programs are filling tremendous requirements arising from industrial concentrations not within easy reach of a university or college. The evolution seems to indicate that off campus programs are not a passing fancy and that such requirements are very likely to be best satisfied in the long run by the establishment of graduate centers with a faculty in residence. As an example, the Polytechnic Graduate Center on Long Island is described. (The Center, actually located in Farmingdale, N. Y., began its operation on September 25, 1961, with a graduate student body of nearly 700 in day and evening programs involving advanced courses in Aerospace Engineering, Electrical Engineering, Electrophysics, Mathematics, Mechanical Engineering, Physics, and Industrial Management. Close to 150 part-time day students are attending on a released-time basis, in addition to 45 full-time students in residence.)     

A microfluidic device for on-chip agarose microbead generation with ultralow reagent consumption

Water-in-oil microdroplets offer microreactors for compartmentalized biochemical reactions with high throughput. Recently, the combination with a sol-gel switch ability, using agarose-in-oil microdroplets, has increased the range of possible applications, allowing for example the capture of amplicons in the gel phase for the preservation of monoclonality during a PCR reaction. Here, we report a new method for generating such agarose-in-oil microdroplets on a microfluidic device, with minimized inlet dead volume, on-chip cooling, and in situ monitoring of biochemical reactions within the gelified microbeads. We used a flow-focusing microchannel network and successfully generated agarose microdroplets at room temperature using the “push-pull” method. This method consists in pushing the oil continuous phase only, while suction is applied to the device outlet. The agarose phase present at the inlet is thus aspirated in the device, and segmented in microdroplets. The cooling system consists of two copper wires embedded in the microfluidic device. The transition from agarose microdroplets to microbeads provides additional stability and facilitated manipulation. We demonstrate the potential of this method by performing on-chip a temperature-triggered DNA isothermal amplification in agarose microbeads. Our device thus provides a new way to generate microbeads with high throughput and no dead volume for biochemical applications.