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1.
This study seeks to promote learning in computer-based learning environments utilizing students’ self-directed metacognitive prompts. Such prompts are based on the idea of instructing students to design their own metacognitive scaffolds and learn with them afterward. In a pre-post experimental design, students in the experimental group (n = 35) were instructed to configure their own metacognitive prompts before learning whereas students in the control group (n = 35) learned without prompts. Log file analysis of navigation behavior indicates that students who learned with their individually designed, self-directed prompts visited relevant webpages significantly more often and spent a longer time on them compared with students in the control group. Moreover, participants in the experimental group attained better transfer performance immediately after learning. The long-term effect in transfer performance was even greater in a follow-up learning session conducted after three weeks without any instructional support in either group. These results are consistent with theories of metacognition and self-regulated learning and indicate that self-directed prompts can lead to sustainable effects.  相似文献   

2.
The present study examines the added value of structuring the peer assessment process, by providing students with a peer feedback template with a varying structuring degree, for the peer feedback content quality in a wiki environment in higher education. The present study took place in the 1st year of a university course in Instructional Sciences (N = 176) and more specifically compared three conditions: no structure peer feedback (control), basic structure peer feedback, and elaborate structure peer feedback condition. Quantitative content analysis of students’ (n = 41) peer feedback messages was performed, and an analysis of (co)variance revealed some discrepancies between the conditions regarding the proportion of peer feedback content categories: (1) peer feedback style, (2) verification type, (3) verification focus, (4) elaboration type, and (5) elaboration focus. This study demonstrated that a higher structuring degree in a peer feedback template during the peer assessment process might have an impact on peer feedback content with respect to the above-mentioned categories; the peer feedback content. Results revealed significant differences between the three conditions regarding the peer feedback content categories. This study illustrated how a practical instructional intervention in the feedback process can increase the potential impact of peer assessment and boost students’ learning in higher education.  相似文献   

3.
The present study aimed at extending research on multimedia design principles by investigating their validity as a function of learners’ reading comprehension and scientific literacy. Students (N = 125; age: M = 15.11 years) learned about cell reproduction during their regular Biology lessons in one of six conditions resulting from cross-varying multimedia (text only vs. text plus animations) and text modality (spoken vs. written vs. spoken and written). Recall and transfer were assessed immediately after learning and again 1 week later. Overall, adding animations to text as well as using spoken rather than written text improved only immediate recall; in addition, a multimedia effect for delayed recall was observed for learners with higher levels of scientific literacy. A redundant presentation of text proved harmful especially for delayed performance measures. Reading comprehension did not moderate multimedia design effects. Students with more suitable cognitive prerequisites were better able to maintain performance from the immediate to the delayed tests. Future multimedia research should further investigate the boundary conditions that moderate multimedia effectiveness.  相似文献   

4.
《Computers & Education》2005,45(4):383-398
In this study, an instructional design model was employed for restructuring a teacher education course with technology. The model was applied in a science education method course, which was offered in two different but consecutive semesters with a total enrollment of 111 students in the fall semester and 116 students in the spring semester. Using tools, such as multimedia authoring tools in the fall semester and modeling software in the spring semester, teacher educators designed high quality technology-infused lessons for science and, thereafter, modeled them in classroom for preservice teachers. An assessment instrument was constructed to assess preservice teachers’ technology competency, which was measured in terms of four aspects, namely, (a) selection of appropriate science topics to be taught with technology, (b) use of appropriate technology-supported representations and transformations for science content, (c) use of technology to support teaching strategies, and (d) integration of computer activities with appropriate inquiry-based pedagogy in the science classroom. The results of a MANOVA showed that preservice teachers in the Modeling group outperformed preservice teachers’ overall performance in the Multimedia group, F = 21.534, p = 0.000. More specifically, the Modeling group outperformed the Multimedia group on only two of the four aspects of technology competency, namely, use of technology to support teaching strategies and integration of computer activities with appropriate pedagogy in the classroom, F = 59.893, p = 0.000, and F = 10.943, p = 0.001 respectively. The results indicate that the task of preparing preservice teachers to become technology competent is difficult and requires many efforts for providing them with ample of opportunities during their education to develop the competencies needed to be able to teach with technology.  相似文献   

5.
Self-association (i.e. interchain aggregation) behavior of atactic poly(ethacrylic acid) PEA in dilute aqueous solution as function of degree-of-neutralization by Na+ counter-ions (i.e. charge fraction f) was investigated by molecular dynamics simulations. Aggregation is found to occur in the range 0  f ≤0.7 in agreement with experimental results compared at specified polymer concentration Cp = 0.36 mol/l in dilute solution. The macromolecular solution was characterized and analysed for radius-of-gyration, torsion angle distribution, inter and intra-molecular hydrogen bonds, radial distribution functions of intermolecular and inter-atomic pairs, inter-chain contacts and solvation enthalpy. The PEA chains form aggregate through attractive inter-chain interaction via hydrogen bonding, in the range f < 0.7, in agreement with experimental observation. The numbers of inter-chain contacts decreases with f. A critical structural transition occurs at f = 0.7, observed via simulations for the first time, in Rg as well as inter-chain H-bonds. The inter-chain distance increases with f due to repulsive interactions between COO− groups on the chains. PEA-PEA electrostatic interactions dominant solvation enthalpy. The PEA solvation enthalpy becomes increasingly favorable with increase in f. The transition enthalpy change, in going from uncharged (acid) state to fully charged state (f = 1) is unfavorable towards aggregate formation.  相似文献   

6.
While critics offer concerns that cyber charter schools under-enroll special education students, such schools may offer advantages for these students, and some cyber schools have identified this market niche. Little is known about such schools. We surveyed parents (n = 232; 48.7% response rate) and students (n = 269; 53.7% response rate) at a cyber charter school that we will call SunTech, where special education students account for 26% of the student body. Findings indicate that special education students and their parents were more likely than general education peers to mention behavioral issues as influencing their decision to choose SunTech. Compared to general education counterparts, special education students and parents reported somewhat higher levels of satisfaction in the school and somewhat lower levels of satisfaction in their prior schools. Implications are discussed.  相似文献   

7.
Digital video is becoming increasingly popular in higher education with faculty digitally recording and broadcasting lectures for students to learn-on-demand, such as iTunes University or YouTube. Students have discovered accelerated playback features in popular computer software and use it to reduce the amount of time watching video-enhanced instruction. In the current study, 147 undergraduate students were randomly assigned to one of six video treatments based on a 3 Video Speed (1.0 = Normal vs. 1.25 = Fast vs. 1.50 = Very Fast) × 2 Captions (Captions Present vs. Captions Absent) × 2 Trial (Trial 1 vs. Trial 2) design. Results show no significant difference on learner performance across treatments based on Video Speed. Captions were found to have a significant negative effect on learner performance. A significant difference was found on learner satisfaction in favor of a normal Video Speed. The findings suggest that learners might be able to accelerate Video Speeds up to 1.5 times the normal speed, but are generally less satisfied with the learning experience.  相似文献   

8.
This paper explores students’ perceptions of creativity in learning Information Technology (IT) in project groups and the implications of better educating creative IT students for the future. Theoretically, the extension of social psychology research into creativity lays the basis of bringing creativity, learning and IT education into one framework. Empirically, qualitative interviews were carried out with 48 students from three disciplines, including Computer Science (n = 16), Electronic Systems (n = 15) and Medialogy (n = 17) at Aalborg University (AAU) in Denmark, which has a tradition of using problem-based learning (PBL) in student project groups. According to the findings, the students’ perceptions of creativity reflect their domain-related conceptualization and tacit learning experience, with different levels of confidence of being creative persons. As IT plays multiple roles in developing students’ creativity, it can be regarded as a ‘learning partner’. This implies that in the future creativity should be taught more explicitly, helping students to become creative IT talents as a part of their professional identity. It also requires teaching efforts to build a learning environment that stimulates creativity more effectively through more interactions between learners, learning tasks and learning tools.  相似文献   

9.
This paper uses a mixed-methods approach to examine the relation between online academic disclosure and academic performance. A multi-ethnic sample of college students (N = 261; male = 66; female = 195; M age ≈ 22 years) responded to open-ended questions about their Facebook use. Thematic analysis revealed that over 14% of the Facebook wall posts/status updates (N = 714) contained academic themes; positive states were more frequent than negative and neutral states and students with lower GPAs expressed negative states more often. A path analysis suggested that academic performance may determine college students’ Facebook use, rather than the reverse. Implications for student support services are discussed.  相似文献   

10.
Carboxylesterases are ubiquitous enzymes with important physiological, industrial and medical applications such as synthesis and hydrolysis of stereo specific compounds, including the metabolic processing of drugs, and antimicrobial agents. Here, we have performed molecular dynamics simulations of carboxylesterase from hyperthermophilic bacterium Geobacillus stearothermophilus (GsEst) for 10 ns each at five different temperatures namely at 300 K, 343 K, 373 K, 473 K and 500 K. Profiles of root mean square fluctuation (RMSF) identify thermostable and thermosensitive regions of GsEst. Unfolding of GsEst initiates at the thermosensitive α-helices and proceeds to the thermostable β-sheets. Five ion-pairs have been identified as critical ion-pairs for thermostability and are maintained stably throughout the higher temperature simulations. A detailed investigation of the active site residues of this enzyme suggests that the geometry of this site is well preserved up to 373 K. Furthermore, the hydrogen bonds between Asp188 and His218 of the active site are stably maintained at higher temperatures imparting stability of this site. Radial distribution functions (RDFs) show similar pattern of solvent ordering and water penetration around active site residues up to 373 K. Principal component analysis suggests that the motion of the entire protein as well as the active site is similar at 300 K, 343 K and 373 K. Our study may help to identify the factors responsible for thermostability of GsEst that may endeavor to design enzymes with enhanced thermostability.  相似文献   

11.
The relationship between the occurrence of simulator sickness (SS) and varying latency in a helmet-mounted display (HMD) was explored in this study. Previous work has always considered latency to be a constant. The aim of this research was to determine if a latency that varied over time would impact the experience of SS for HMD users. An object location task was used while viewing real, live video scenes via HMD. A planned comparisons approach was utilized with four experimental conditions, 2 of them having constant latency (0 ms added to system baseline, 200 ms added to system baseline) and 2 of them having sinusoidally varying latency (100 ms amplitude at 0.2 Hz frequency, and 20–100 ms varying amplitude at 0.2 Hz frequency). These conditions allowed for the assessment of the effects of constant latency vs. varying latency on the experience of SS. The results indicated that a varying latency is associated with greater experience of SS among HMD users than constant latency. Results also indicated, as has other recent research, that added constant latency on its own does not appear to be associated with the experience of higher levels of SS in an HMD.  相似文献   

12.
《Applied ergonomics》2011,42(1):138-145
IntroductionSubjective workload measures are usually administered in a visual–manual format, either electronically or by paper and pencil. However, vocal responses to spoken queries may sometimes be preferable, for example when experimental manipulations require continuous manual responding or when participants have certain sensory/motor impairments. In the present study, we evaluated the acceptability of the hands-free administration of two subjective workload questionnaires – the NASA Task Load Index (NASA-TLX) and the Multiple Resources Questionnaire (MRQ) – in a surgical training environment where manual responding is often constrained.MethodSixty-four undergraduates performed fifteen 90-s trials of laparoscopic training tasks (five replications of 3 tasks – cannulation, ring transfer, and rope manipulation). Half of the participants provided workload ratings using a traditional paper-and-pencil version of the NASA-TLX and MRQ; the remainder used a vocal (hands-free) version of the questionnaires. A follow-up experiment extended the evaluation of the hands-free version to actual medical students in a Minimally Invasive Surgery (MIS) training facility.ResultsThe NASA-TLX was scored in 2 ways – (1) the traditional procedure using participant-specific weights to combine its 6 subscales, and (2) a simplified procedure – the NASA Raw Task Load Index (NASA-RTLX) – using the unweighted mean of the subscale scores. Comparison of the scores obtained from the hands-free and written administration conditions yielded coefficients of equivalence of r = 0.85 (NASA-TLX) and r = 0.81 (NASA-RTLX). Equivalence estimates for the individual subscales ranged from r = 0.78 (“mental demand”) to r = 0.31 (“effort”). Both administration formats and scoring methods were equally sensitive to task and repetition effects. For the MRQ, the coefficient of equivalence for the hands-free and written versions was r = 0.96 when tested on undergraduates. However, the sensitivity of the hands-free MRQ to task demands (ηpartial2 = 0.138) was substantially less than that for the written version (ηpartial2 = 0.252). This potential shortcoming of the hands-free MRQ did not seem to generalize to medical students who showed robust task effects when using the hands-free MRQ (ηpartial2 = 0.396). A detailed analysis of the MRQ subscales also revealed differences that may be attributable to a “spillover” effect in which participants’ judgments about the demands of completing the questionnaires contaminated their judgments about the primary surgical training tasks.ConclusionVocal versions of the NASA-TLX are acceptable alternatives to standard written formats when researchers wish to obtain global workload estimates. However, care should be used when interpreting the individual subscales if the object is to make comparisons between studies or conditions that use different administration modalities. For the MRQ, the vocal version was less sensitive to experimental manipulations than its written counterpart; however, when medical students rather than undergraduates used the vocal version, the instrument’s sensitivity increased well beyond that obtained with any other combination of administration modality and instrument in this study. Thus, the vocal version of the MRQ may be an acceptable workload assessment technique for selected populations, and it may even be a suitable substitute for the NASA-TLX.  相似文献   

13.
The present study integrates cognitive and affective aspects of media processing in order to make an argument for reexamining the current cold cognition perspective in multimedia research in favor of a more integrative perspective. The Cognitive-Affective-Theory-of-Learning-with-Media (CATLM) assumes that students need to become motivated to make full use of their cognitive resources. Therefore, and even though seductive details (sds) are additional interesting but unnecessary pieces of information that do not conform with the coherence principle, their possible motivational role should not be dismissed. Using a 2 × 3-experimental design, participants (N = 123) were asked to learn about biology with multimedia instruction that manipulated modality (text vs. narration) and presence of seductive details (no-sds vs. textual-sds vs. narrated-sds). Results of variance analyses show a modality effect. In addition, moderated mediation analyses with the moderator modality and mediator situational interest confirm the affective mediation assumption with the following two conditional effects. A direct detrimental effect of seductive details on learning performance under the text-condition and an indirect compensatory effect under the narration-condition were shown.  相似文献   

14.
ObjectiveThe purpose of this study was to assess associations between depression and problematic internet use (PIU) among female college students, and determine whether Internet use time moderates this relationship.MethodThis cross-sectional survey included 265 female college students from four U.S. universities. Students completed the Patient Health Questionnaire-9 (PHQ-9), the Problematic and Risky Internet Use Screening Scale (PRIUSS) and self-reported daily Internet use. Analyses included multivariate analysis of variance and Poisson regression.ResultsParticipants reported mean age of 20.2 years (SD = 1.7) and were 84.9% Caucasian. The mean PHQ-9 score was 5.4 (SD = 4.6); the mean PRIUSS score was 16.4 (SD = 11.1). Participants’ risk for PIU increased by 27% with each additional 30 min spent online using a computer (RR = 1.27, 95% CI: 1.14–1.42, p < .0001). Risk for PIU was significantly increased among those who met criteria for severe depression (RR = 8.16 95% CI: 4.27–15.6, p < .0001). The PHQ-9 items describing trouble concentrating, psychomotor dysregulation and suicidal ideation were most strongly associated with PIU risk.ConclusionsThe positive relationship between depression and PIU among female college students supports screening for both conditions, particularly among students reporting particular depression symptoms.  相似文献   

15.
This article uses eye-tracking technology to examine how study activities such as taking notes or filling in a graphic organizer affect cognitive processing during learning. College students read a computer-presented passage that compared the characteristics of eastern steamboats (top section) and western steamboats (bottom section), either by reading it twice (read-only group), typing notes into a textbox on the right side of the screen (note-taking group), or typing characteristics of the two types of steamboats into a compare-and-contrast graphic organizer on the right side of the screen (graphic organizer group). Compared to the note-taking group, the graphic organizer group displayed more eye movements between the top and bottom of the passage (i.e., integrative saccades, d = 1.03), more eye movements between the text and the type-in window on the right side (i.e., constructive saccades, d = 0.79), fewer constructive saccades during initial reading (d = −0.64), and less time looking to the right side during initial reading (d = −0.81); and scored higher on a comprehension test given afterwards (d = 1.17), although both study groups outscored the read-only group. Results suggest that students in the note-taking group (and read-only group) tended to use a linear learning strategy in which their eyes followed the text in the order presented whereas students in the graphic organizer group tended to use a generative learning strategy in which their eyes searched for connections between specific information across the passage required to make comparisons.  相似文献   

16.
17.
This article aims at finding efficient hyperspectral indices for the estimation of forest sun leaf chlorophyll content (CHL, µg cmleaf? 2), sun leaf mass per area (LMA, gdry matter mleaf? 2), canopy leaf area index (LAI, m2leaf msoil? 2) and leaf canopy biomass (Bleaf, gdry matter msoil? 2). These parameters are useful inputs for forest ecosystem simulations at landscape scale. The method is based on the determination of the best vegetation indices (index form and wavelengths) using the radiative transfer model PROSAIL (formed by the newly-calibrated leaf reflectance model PROSPECT coupled with the multi-layer version of the canopy radiative transfer model SAIL). The results are tested on experimental measurements at both leaf and canopy scales. At the leaf scale, it is possible to estimate CHL with high precision using a two wavelength vegetation index after a simulation based calibration. At the leaf scale, the LMA is more difficult to estimate with indices. At the canopy scale, efficient indices were determined on a generic simulated database to estimate CHL, LMA, LAI and Bleaf in a general way. These indices were then applied to two Hyperion images (50 plots) on the Fontainebleau and Fougères forests and portable spectroradiometer measurements. They showed good results with an RMSE of 8.2 µg cm? 2 for CHL, 9.1 g m? 2 for LMA, 1.7 m2 m? 2 for LAI and 50.6 g m? 2 for Bleaf. However, at the canopy scale, even if the wavelengths of the calibrated indices were accurately determined with the simulated database, the regressions between the indices and the biophysical characteristics still had to be calibrated on measurements. At the canopy scale, the best indices were: for leaf chlorophyll content: NDchl = (ρ925 ? ρ710)/(ρ925 + ρ710), for leaf mass per area: NDLMA = (ρ2260 ? ρ1490)/(ρ2260 + ρ1490), for leaf area index: DLAI = ρ1725 ? ρ970, and for canopy leaf biomass: NDBleaf = (ρ2160 ? ρ1540)/(ρ2160 + ρ1540).  相似文献   

18.
This paper presents a new bi-side gate driver integrated by indium-zinc-oxide thin film transistors (IZO TFTs). Our optimized operate method can achieve high speed performance by employing a lower duty ratio (25%) CK2 with its pulse located in the middle of the pulse of CK2L to fully use the bootstrapped high voltage of node Q. In addition, the size of devices is optimized by calculation and simulation, and the function of the proposed gate driver is predicted by the circuit simulation. Furthermore, the proposed gate driver with 20 stages is fabricated by the IZO TFTs process. It is shown that a 2.6 μs width pulse with good noise-suppressed characteristic can be successfully output at the condition of Rload = 6 kΩ and Cload = 150 pF. The power consumption of the proposed gate driver with 20 stages is measured as 1 mW. Hence, the proposed gate driver may be applied to the display of 4K resolution (4096 × 2160) at a frame rate of 120 Hz. Moreover, there is a good stability for the proposed gate driver under 48 h operation.  相似文献   

19.
Variation in the foliar chemistry of humid tropical forests is poorly understood, and airborne imaging spectroscopy could provide useful information at leaf and canopy scales. However, variation in canopy structure affects our ability to estimate foliar properties from airborne spectrometer data, yet these structural affects remain poorly quantified. Using leaf spectral (400–2500 nm) and chemical data collected from 162 Australian tropical forest species, along with partial least squares (PLS) analysis and canopy radiative transfer modeling, we determined the strength of the relationship between canopy reflectance and foliar properties under conditions of varying canopy structure.At the leaf level, chlorophylls, carotenoids and specific leaf area (SLA) were highly correlated with leaf spectral reflectance (r = 0.90–0.91). Foliar nutrients and water were also well represented by the leaf spectra (r = 0.79–0.85). When the leaf spectra were incorporated into the canopy radiative transfer simulations with an idealistic leaf area index (LAI) = 5.0, correlations between canopy reflectance spectra and leaf properties increased in strength by 4–18%. The effects of random LAI (= 3.0–6.5) variation on the retrieval of leaf properties remained minimal, particularly for pigments and SLA (r = 0.92–0.93). In contrast, correlations between leaf nitrogen (N) and canopy reflectance estimates decreased from r = 0.87 at constant LAI = 5 to r = 0.65 with randomly varying LAI = 3.0–6.5. Progressive increases in the structural variability among simulated tree crowns had relatively little effect on pigment, SLA and water predictions. However, N and phosphorus (P) were more sensitive to canopy structural variability. Our modeling results suggest that multiple leaf chemicals and SLA can be estimated from leaf and canopy reflectance spectroscopy, and that the high-LAI canopies found in tropical forests enhance the signal via multiple scattering. Finally, the two factors we found to most negatively impact leaf chemical predictions from canopy reflectance were variation in LAI and viewing geometry, which can be managed with new airborne technologies and analytical methods.  相似文献   

20.
Current research examines the need for design and validation of a unifactorial scale to measure attitudes of university teachers with regard to ICT. The main goal of this study is to achieve a simple scale, composed of a single factor contributing a clearly reliable measure with acceptable content and factorial validity. A case study is presented, which has been developed with the teaching staff of the University of Salamanca (Spain). In this case study, an expert content validation was done at a first stage. After that, an attitude scale regarding the usage of ICT in teaching was applied with a representative sample of teachers (N = 2329; n = 161). An individual analysis of the items was made with the obtained results and then a Cronbach’s alpha based reliability test was carried out to show the internal consistency of the survey. Finally, an exploratory and confirmatory factor analysis was applied to prove its structural soundness and unifactoriality. The main conclusion of this paper is to offer to the scientific community a tool with adequate psychometric properties that gives added pedagogical value to the introduction of ICT in higher education teaching.  相似文献   

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