Does a contextualized theory of planned behavior explain why teenagers stay in virtual worlds?

Academics and business practitioners are intrigued by the factors that foster continued user engagement in virtual worlds (VWs). It is unclear how, and to what extent, existing theories can explain their continued use. As young people constitute the majority of VW users, understanding the reasons for their continued use intentions is important. Taking the distinctive features of VW services into account, such as the visibility of users’ actions to other users, we contextualize the Theory of Planned Behavior and investigate the role of teenagers’ attitudes, social influences and perceived behavioral control as the determinants of their continued intention to use VW. We then apply a set of constructs from prior Information Systems (IS) literature to decompose these constructs. By analyzing primary data collected from 923 users of Habbo Hotel, a leading virtual world for teenagers, this study confirms the role of users’ intrinsic motivation, interpersonal influence and self-efficacy as key constituents of sustained user engagement in VWs. In addition, we demonstrate that decomposing these three established constructs can capture many of the key contextual characteristics of VWs. The study contributes to the literature by showing that IS theories and constructs are appropriate for the VW setting and teenage users.     

Testing Measurement Invariance in the Target Rotated Multigroup Exploratory Factor Model

We propose a method to investigate measurement invariance in the multigroup exploratory factor model, subject to target rotation. We consider both oblique and orthogonal target rotation. This method has clear advantages over other approaches, such as the use of congruence measures. We demonstrate that the model can be implemented readily in the freely available Mx program. We present the results of 2 illustrative analyses, one based on artificial data, and the other on real data relating to personality in male and female psychology students.     

Effects and side effects of inspections and accountability in education: an overview of empirical studies

This paper presents an overview of studies into effects and side effects of control mechanisms in education. We focus on effects and side effects of inspection visits and public performance indicators. A first conclusion is that the studies do not provide us with a clear answer to the question of whether inspections have positive causal effects on the quality of schools. Results of studies of publications on public performance indicators are more unambiguous. They lead us to the conclusion that although principals and teachers believe performance indicators are important, parents and pupils take very little notice of these indicators when choosing schools. A third conclusion concerns the occurrence of side effects of school inspections and other control mechanisms in education. Several of the studies discussed clearly refer to the existence of these side effects, such as ‘window dressing’ and other types of ‘gaming’.     

GraphoGame SI: the development of a technology-enhanced literacy learning tool for Standard Indonesian

Early intervention programs are generally considered the most efficient and beneficial approach to providing support to struggling beginning readers. This paper discusses the theoretical background, development, and design of, as well as the first results obtained with, GraphoGame for Standard Indonesian, a technology-enhanced learning environment that trains the basic skills of reading by high but playful exposure to grapheme-phoneme coupling. The results of the pilot study assessing the usability of the program in 69 first-graders show that the more the students with low pre-test phonological skills were exposed to the game, the better their post-test performance on reading and decoding fluency became. Although large-scale, randomized controlled studies are needed to confirm the effectiveness of GraphoGame SI, these promising first results may offer a stepping stone for the development of additional language versions and future systematic comparisons of the method’s results in different languages and populations.     

Directionality effects in simultaneous language interpreting: the case of sign language interpreters in The Netherlands

The quality of interpretations produced by sign language interpreters was investigated. Twenty-five experienced interpreters were instructed to interpret narratives from (a) spoken Dutch to Sign Language of The Netherlands (SLN), (b) spoken Dutch to Sign Supported Dutch (SSD), and (c) SLN to spoken Dutch. The quality of the interpreted narratives was assessed by 5 certified sign language interpreters who did not participate in the study. Two measures were used to assess interpreting quality: the propositional accuracy of the interpreters' interpretations and a subjective quality measure. The results showed that the interpreted narratives in the SLN-to-Dutch interpreting direction were of lower quality (on both measures) than the interpreted narratives in the Dutch-to-SLN and Dutch-to-SSD directions. Furthermore, interpreters who had begun acquiring SLN when they entered the interpreter training program performed as well in all 3 interpreting directions as interpreters who had acquired SLN from birth.     

Detection of macroenzymes: establishing upper reference limits for eight enzymes after polyethylene glycol precipitation

IntroductionThe presence of macroenzymes in blood can cause diagnostic confusion. Therefore, confirming the presence of macroenzymes is important to reduce unnecessary (non-)invasive investigations. Polyethylene glycol (PEG) precipitation is a simple and fast first-line method for the detection of macroenzymes. However, there is no consensus on the upper reference limit for the PEG-precipitable activity (%PPA) of monomeric enzymes. The aim of this study was to verify a PEG precipitation protocol for the detection of macroenzymes in our laboratory by establishing upper reference limits (URLs) and determining imprecision for eight enzymes after PEG precipitation. In addition, we aimed to clinically verify the URLs using samples containing macroenzymes as identified by electrophoresis.Materials and methodsPer enzyme, at least 40 leftover blood samples from adult patients with either normal or increased enzyme activities were diluted 1:1 with 25% PEG 6000 and 1:1 with 0.9% NaCl. Mixtures were incubated for 10 min at 37°C and centrifuged. Supernatant enzyme activity was measured on Cobas c702 and the %PPA was calculated.ResultsThe following URLs were obtained: 26% PPA for amylase, 29% PPA for alkaline phosphatase (ALP), 61% PPA for alanine aminotransferase, 48% PPA for aspartate aminotransferase, 24% PPA for creatine kinase (CK), 55% PPA for gamma-glutamyltransferase, 65% PPA for lactate dehydrogenase, and 56% PPA for lipase. The within-lab imprecision was < 15%. Regarding the clinical verification, the two historical samples with proven macroCK showed a %PPA of 69% and 43%, respectively, and a sample with proven macroALP had a %PPA of 52%.ConclusionIn this study, URLs for monomeric enzyme activities after PEG precipitation for eight different enzymes were established. The URLs are suitable for clinical use, but are only partially in line with other studies. Therefore, our data highlight the importance of establishing laboratory-specific upper reference limits for %PPA to allow a correct interpretation.     

Exploring the role of assessment criteria during teachers’ collaborative judgement processes of students’ portfolios

Student portfolios are increasingly used for assessing student competences in higher education, but results about the construct validity of portfolio assessment are mixed. A prerequisite for construct validity is that the portfolio assessment is based on relevant portfolio content. Assessment criteria, are often used to enhance this condition. This study aims to identify whether assessment criteria can improve content, argumentation and communication during teacher moderation while judging student portfolios. Six teachers scored 32 student portfolios in dyads with and without assessment criteria. Their judgement processes were qualitatively analysed. Results indicated that the quality of their judgement processes was low, since teachers based their judgements mainly on their own personal opinion and less on evidence found in the portfolio. Teachers barely paid attention to quality checks and easily agreed with each other. When teachers used assessment criteria, the quality of their judgements slightly improved. They based their judgements more on relevant evidence, used less personal experiences and more often checked the quality of their judgement processes. It is concluded that the quality of teacher portfolio judgement is low, and that the use of assessment criteria can enhance its quality.     

The effects of changeover delays of fixed or variable duration on concurrent variable-interval performance in pigeons

The effects of changeover delays of fixed or variable duration on concurrent variable-interval performance in pigeons were investigated in a series of three experiments. Experiment 1 compared the effects of a fixed, variable, or variable signaled changeover delay on interchangeover times and responding during and after the changeover delay. The duration of the changeover delays was systematically varied in Experiment 2, and the relative reinforcement frequencies were manipulated in Experiment 3. Interchangeover times were found to be shorter when changeover delays of variable duration were compared with those of fixed duration. Changeover delays of fixed duration produced higher response rates during the changeover delay than after the changeover delay had elapsed; changeover delays of variable duration produced such differences to a lesser extent. It was concluded that the changeover delay in concurrent variable-interval schedules of reinforcement functionally acts as a delay period to the next opportunity for reinforcement, possibly serving as a conditioned reinforcer for the behavior preceding it (the interchangeover time) and as a discriminative stimulus for the behavior in its presence (response rates during the delay).     

Spatial matching and nonmatching in male and female Wistar rats: Effects of delay-interval duration

Male and female Wistar rats were trained in a delayed matching-to-position procedure in which one of the two levers (sample) was presented. Pressing this lever resulted in its retraction and began a delay interval of random variable duration, which terminated with the occurrence of the first nose poke in the pellet retrieval unit after the delay interval had expired. Both levers were then inserted into the chamber, and food became available when the subject pressed the lever that had previously been pressed (matching response). When the subject failed to make a matching response, time out (5 sec) was presented. In the next experimental condition, nonmatching was reinforced. Males and females required an equal number of trials to attain 80% accuracy during three consecutive sessions under matching and nonmatching conditions. Response accuracy decreased as the delay interval increased, during both conditions. Differences between the sexes were not observed, suggesting that memory functions in male and female rats may only differ when other behavioral differences between the sexes are allowed to interfere with the assessment of memory functioning.     

Simulation study of item bias detection with restricted factor analysis

Restricted factor analysis (RFA) can be used to detect item bias (also called differential item functioning). In the RFA method of item bias detection, the common factor model serves as an item response model, but group membership is also included in the model. Two simulation studies are reported, both showing that the RFA method detects bias in 7‐point scale items very well, especially when the sample size is large, the mean trait difference between groups is small, the group sizes are equal, and the amount of bias is large. The first study further shows that the RFA method detects bias in dichotomous items at least as well as an established method based on the one‐parameter logistic item response model. The second study concerns various procedures to evaluate the significance of two‐item bias indices provided by the RFA method. The results indicate that the RFA method performs best when it is used in an iterative procedure.