Although the use of computerized assessment tools in educational and psychological settings has increased dramatically in recent years, limited information is available about the properties of computerized self-concept measures. The authors evaluated the characteristics of computerized and paper-and-pencil versions of the Rosenberg Self-Esteem Scale (SES)—one of the most widely used self-concept measures in educational and psychological research. Results showed that administration mode (computerized versus paper and pencil) had little effect on the psychometric properties of the SES (i.e., score magnitude, variability, and factor structure) but that the computerized version took longer and was preferred by examinees. With the exception of administration time, these results support the use of the computerized SES and its comparability to the paper-and-pencil version.

Distilled water, a carbohydrate-electrolyte (CE; 4% sucrose, 2% glucose, 17.2 meq/l NaCl, and 2.8 meq/l KCl) solution, or a 10% glucose solution, all containing the nonabsorbed indicator polyethylene glycol (PEG) and deuterium oxide (D2O, 30 ppm), were infused (15 ml/min) into the duodenojejunum of seven men by using the triple lumen technique. Net water absorption was determined directly from the change in PEG concentration and was calculated from plasma D2O derived from D2O in the perfusion solutions. The protocol included a 45-min equilibration period followed by a 90-min test period. Intestinal samples were drawn at 10-min intervals from 15 to 45 min and at 15-min intervals thereafter. Blood was drawn at 45, 50, 55, 60, 75, 90, 105, 120, and 135 min. Intestinal samples were analyzed for D2O, Na+, K+, osmolality, PEG, and glucose; blood was analyzed for D2O. Results (+/- SE; positive values secretion, negative values absorption) showed net fluid absorption from distilled water (-9.40 +/- 1.28 ml.h-1.cm-1) and the CE (-13.30 +/- 1.22 ml.h-1.cm-1) solution, but net secretion (4.40 +/- 1.25 ml.h-1.cm-1) from the 10% glucose solution. All values were significantly (P less than 0.05) different from each other. Perfusing the CE solution caused net Na+ and K+ absorption, whereas perfusing the 10% dextrose solution caused net electrolyte secretion. Rates of D2O accumulation in the plasma were independent of the solutions perfused.(ABSTRACT TRUNCATED AT 250 WORDS)

Previous simulation studies of computerized adaptive tests (CATs) have revealed that the validity and precision of proficiency estimates can be maintained when review opportunities are limited to items within successive blocks. Our purpose in this study was to evaluate the effectiveness of CATs with such restricted review options in a live testing setting. Vocabulary CATs were compared under four conditions: (a) no item review allowed, (b) review allowed only within successive 5‐item blocks, (c) review allowed only within successive lO‐item blocks, and (d) review allowed only after answering all 40 items. Results revealed no trust‐worthy differences among conditions in vocabulary proficiency estimates, measurement error, or testing time. Within each review condition, ability estimates and number correct scores increased slightly after review, more answers were changed from wrong to right than from right to wrong, most examinees who changed answers improved proficiency estimates by doing so, and nearly all examinees indicated that they had an adequate opportunity to review their previous answers. These results suggest that restricting review opportunities on CATs may provide a viable way to satisfy examinee desires, maintain validity and measurement precision, and keep testing time at acceptable levels.

We studied gastric and intestinal function by gastric intubation/intestinal perfusion in six healthy male volunteers to evaluate optimal use of a 6% glucose-electrolyte (GES) solution. Gastric volume, residual volume, emptying rate, and secretion were measured for an initial 763 +/- 19 ml gastric load of GES and at the beginning and end of four additional gastric loads (2.2 ml.kg-1; approximately 180 ml) given at 10-min intervals. The relatively high gastric (713 +/- 58 ml) and residual (507 +/- 26 ml) volumes maintained a high gastric emptying rate (19.5 +/- 1.4 ml.min-1). Composition of the GES emptied into the duodenum was also measured in this first experiment. In a second experiment, this modified solution was infused (triple lumen tube) into the duodenum at a rate equal to gastric emptying rate, or at 38 or 77% greater rates. Absorption of water (11.3-12.9 ml.h-1.cm-1) and glucose 4.3-5.6 mmol.h-1.cm-1) were similar at all perfusion rates during the second experiment. We conclude that duodenojejunal segmental absorption rates of water and glucose produced by a rapid, sustained gastric emptying rate cannot be increased by delivering a greater load of glucose and water by intestinal perfusion.

Intestinal absorption was measured in six trained male cyclists during rest, exercise, and recovery periods with the segmental perfusion technique. Each subject passed a multilumen tube into the duodenojejunum. The experiments consisted of 1) a sequence of 1-h bouts of cycling exercise at 30, 50, and 70% maximal O2 uptake (Vo2max) separated by 1-h rest periods or 2) a 90-min bout at 70% VO2max. The cycling was performed on a constant-load Velodyne trainer. Absorption of water and a 6% carbohydrate-electrolyte (2% glucose, 6% sucrose, 20 meq Na+, 2.6 meq K+) solution (both perfused at 15 ml/min) were compared. The effects of perfusing an isotonic electrolyte solution during mild (30% VO2max) exercise were also studied. Fluid was sampled every 10 min from ports 10 and 50 cm distal to the infusion site. Water flux was determined by differences in polyethylene glycol concentration across the 40-cm test segment. Results showed 1) no difference in water or electrolyte absorption rates among rest, exercise, and recovery periods; 2) no difference in absorption rates among the three exercise intensities or different exercise durations; and 3) significantly greater fluid absorption rates from the carbohydrate-electrolyte (CE) solution than from water. Water flux during rest, exercise, and recovery was about sixfold greater from the CE solution than from the isotonic solution without carbohydrate. We conclude that 1) exercise has no effect on water or solute absorption in the duodenojejunum, 2) fluid absorption occurs significantly faster from a CE solution than from water, and 3) fluid absorption is increased sixfold by addition of carbohydrate to an electrolyte solution.

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Recent simulation studies indicate that there are occasions when examinees can use judgments of relative item difficulty to obtain positively biased proficiency estimates on computerized adaptive tests (CATs) that permit item review and answer change. Our purpose in the study reported here was to evaluate examinees' success in using these strategies while taking CATs in a live testing setting. We taught examinees two item difficulty judgment strategies designed to increase proficiency estimates. Examinees who were taught each strategy and examinees who were taught neither strategy were assigned at random to complete vocabulary CATs under conditions in which review was allowed after completing all items and when review was allowed only within successive blocks of items. We found that proficiency estimate changes following review were significantly higher in the regular review conditions than in the strategy conditions. Failure to obtain systematically higher scores in the strategy conditions was due in large part to errors examinees made in judging the relative difficulty of CAT items.

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