The effect of a pretest in an interactive,multimodal pretraining system for learning science concepts

Multiple traits of language proficiency as well as test method effects were concurrently analyzed to investigate interrelations of construct validity, convergent validity, and discriminant validity using multitrait-multimethod (MTMM) matrices. A total of 585 test takers' scores were derived from the field test of the Pearson Test of English Academic. An MTMM confirmatory factor analysis model was parameterized using 4 traits and 3 assessment methods. The 4 traits included listening, reading, speaking, and integrated skills, while the 3 methods included prescribed multiple-choice responses, constructed responses, and summarized responses. The trait factor loadings were systematically greater than those of methods, providing evidence that the indicators were strongly related to their latent constructs, after adjusting for the method effects. The results showed robust convergent validity, moderate discriminant validity, and insignificant method effects. Implications are discussed.     

Behavior of Asymptotically Distribution Free Test Statistics in Covariance Versus Correlation Structure Analysis

The asymptotically distribution free (ADF) method is often used to estimate parameters or test models without a normal distribution assumption on variables, both in covariance structure analysis and in correlation structure analysis. However, little has been done to study the differences in behaviors of the ADF method in covariance versus correlation structure analysis. The behaviors of 3 test statistics frequently used to evaluate structural equation models with nonnormally distributed variables, χ² test T_AGLS and its small-sample variants T_YB and T_F(AGLS) were compared. Results showed that the ADF method in correlation structure analysis with test statistic T_AGLS performs much better at small sample sizes than the corresponding test for covariance structures. In contrast, test statistics T_YB and T_F(AGLS) under the same conditions generally perform better with covariance structures than with correlation structures. It is proposed that excessively large and variable condition numbers of weight matrices are a cause of poor behavior of ADF test statistics in small samples, and results showed that these condition numbers are systematically increased with substantial increase in variance as sample size decreases. Implications for research and practice are discussed.     

Promoting Pre-service Elementary Students' Understanding of Chemical Equilibrium through Discussions in Small Groups

The purpose of this study was to investigate the effectiveness of small group discussion on students' conceptual understanding of chemical equilibrium. Students' understanding of chemical equilibrium concepts was measured using the Misconception Identification Test. The test consisted of 30 items and administered as pre-posttests to a total of 81 pre-service elementary students in two intact classes of the same university. One of the classes was randomly assigned as experimental group (n = 40) which was instructed with discussion propositions related to chemical equilibrium concepts in small group and the other class was assigned as control group (n = 41) which was instructed through traditionally designed chemistry instruction. Analysis of covariate (ANCOVA) was used to determine treatment effects on students' conceptual understanding of chemical equilibrium when pre-test result was used a covariate. The analysis of results showed a statistically significant difference between the experimental and control groups' posttest mean scores in favor of the experimental group after treatment (F(1,78) = 47,77; P < 0.05). The results indicated that while the average percentage of students in the experimental group holding a scientifically correct concept had risen from 35.0% to 59.1%, a gain of 24.1%, the percentage of correct responses of the students in the control group had increased from 32.5% to 43.82%, a gain of 11.32% after treatment. In addition, the percentages of students' correct responses and keyed misconceptions on posttest results were discussed for six areas related to: (1) the mass vs. concentration, (2) rate vs. extent, (3) constancy of the equilibrium constant, (4) misuse of Le Chatelier's principle, (5) constant concentration, and (6) competing equilibria related to chemical equilibrium concepts in experimental and control groups.     

Potential use of cucumber (Cucumis sativus L.) endophytic fungi as seed treatment agents against root-knot nematode Meloidogyne incognita

Seed treatment with endophytic fungi has been regarded as an effective method for plant parasitic nematode control. Endophytic fungi from cucumber seedlings were isolated and screened for their potential to be used as seed treatment agents against Meloidogyne incognita. Among the 294 isolates screened, 23 significantly reduced galls formed by M. incognita in greenhouse test. The 10 most effective isolates were Fusarium (5), Trichoderma (1), Chaetomium (1), Acremonium (1), Paecilomyces (1), and Phyllosticta (1). Their control efficacies were repeatedly tested and their colonizations as well as in vitro activity against M. incognita were studied. They reduced the number of galls by 24.0%–58.4% in the first screening and 15.6%–44.3% in the repeated test, respectively. Phyllosticta Ph511 and Chaetomium Ch1001 had high colonizations on both the roots and the aboveground parts of cucumber seedlings. Fusarium isolates had colonization preference on the roots, their root colonizations ranging from 20.1% to 47.3% of the total root area. Trichoderma Tr882, Paecilomyces Pa972, and Acremonium Ac985 had low colonizations on both the roots and the aboveground parts. Acremonium Ac985, Chaetomium Ch1001, Paecilomyces Pa972, and Phyllosticta Ph511 produced compounds affecting motility of the second stage juveniles of M. incognita. Based on these results, Chaetomium Ch1001 was considered to have the highest potential as a seed treatment agent for M. incognita biocontrol.     

Building an organized knowledge base: Concept mapping and achievement in secondary school physics

Direct teaching of problem-solving methods to high school physics students met with little success. Expert problem solving depended upon an organized knowledge base. Concept mapping was found to be a key to organizing an effective knowledge base. The investigation of the effect of the degree of concept mapping on achievement was the purpose of this study. Six intact high school physics classes, taught by this investigator, took part in the study. Two classes were control groups and received standard instruction. Four classes received six weeks of concept-mapping instruction prior to the unit under study. Two of these four classes were the low-level treatment group and were required to submit concept maps at the conclusion of the instruction. The other two classes were the high-level treatment group and were required to submit concept maps at the beginning and at the conclusion of the unit under study. One class from each treatment group took a pretest prior to instruction. An analysis of the posttest results revealed no pretest sensitization. A one-way analysis of covariance indicated a significant main effect for the treatment level at the p < 0.05 level. A pair of single-df comparisons of the adjusted treatment means resulted in significant differences (p < 0.05) between the control group and the average of the treatment means as well as between the two experimental groups. It can be concluded that for this sample (upper-middle-class high school physics students) mapping concepts prior to, during, and subsequent to instruction led to greater achievement as measured by posttest scores.     

Reliability analysis of DOOF for weibull distribution

Hierarchical Bayesian method for estimating the failure probabilityp _i under DOOF by taking the quasi-Beta distributionB(p _i−1, 1, 1,b) as the prior distribution is proposed in this paper. The weighted Least Squares Estimate method was used to obtain the formula for computing reliability distribution parameters and estimating the reliability characteristic values under DOOF. Taking one type of aerospace electrical connector as an example, the correctness of the above method through statistical analysis of electrical connector accelerated life test data was verified. Project (No. 59975081) supported by the National Natural Science Foundation of China     

Stress intensity factors under combined bending and torsion moments

This paper discusses stress intensity factor (SIF) calculations for surface cracks in round bars subjected to combined torsion and bending loadings. Different crack aspect ratios, a/b, ranging from 0.0 to 1.2 and relative crack depths, a/D, ranging from 0.1 to 0.6 were considered. Since the loading was non-symmetrical for torsion loadings, a whole finite element model was constructed. Then, the individual and combined bending and torsion loadings were remotely applied to the model. The equivalent SIF method, F*_EQ, was then used explicitly to combine the individual SIFs from the bending and torsion loadings. A comparison was then carried out with the combined SIF, F*_FE, obtained using the finite element analysis (FEA) under similar loadings. It was found that the equivalent SIF method successfully predicted the combined SIF for Mode I. However, discrepancies between the results determined from the different approaches occurred when F _III was involved. It was also noted that the predicted F*_FE using FEA was higher than the F*_EQ predicted through the equivalent SIF method due to the difference in crack face interactions.     

The Finnish public discussion of giftedness and gifted children

The purpose of this paper is to present the results of research in which the Finnish public discussion of giftedness and gifted children, and conceptions of giftedness and gifted children presented in it, were examined. The research was conducted by analyzing articles from the Finnish newspaper Helsingin Sanomat and the teachers’ periodical Opettaja, using the content analysis method. The results show that giftedness is seen as multidimensional, and both intrapersonal and environmental contributions are recognized as essential in talent development. The conceptions of gifted children were quite diverse, and gifted children’s possible problems were frequently discussed. Moreover, misunderstandings were revealed as well as areas that have not been adequately addressed.     

Increased frequency and planning: A more effective approach to guided reading in Grade 2

This yearlong quasi experimental study examined the effects of two approaches to guided reading on second-grade students' reading abilities. The 79 subjects were chosen as a nonprobability sample and served as the treatment and comparison groups. The groups were pre- and post tested using the Developmental Reading Assessment, Second Edition determine students' reading levels. A 2 × 2 repeated measures analysis of variance revealed significant main and interaction effects. According to a post hoc analysis of mean difference effect size, both groups experienced very large effects, but treatment effects (d = 3.66) were much larger than the comparison (d = 1.34). The results suggest that increased emphasis on guided reading can lead to a greater impact on second-grade students' reading ability.     

Effects of method and format on subjects' responses to a control of variables reasoning problem

Excessive time and training demands have rendered Piaget's clinical method of reasoning assessment impractical for researchers and science teachers who work with large numbers of students. The published literature

1 See: Lawson, A. E. Journal of Research in Science Teaching, 1978, 15 (1), 11-24; Shayer, M., Adey, P., & Wylam, H. Journal of Research in Science Teaching, 1981, 18 (2), 157-168; Staver, J. R., & Gabel, D. L. Journal of Research in Science Teaching, 1979, 16 (6), 534-544; Tobin, K. G., & Capie, W. Educational and Psychological Measurement, 1981, 41 (2), 413-424.

indicates that reliable, valid alternatives to clinical assessment are feasible. However, the overestimate/underestimate of reasoning for different methods and formats remains unresolved through research. The objective of this study was to determine the effects of various methods and formats on subjects' responses to a Piagetian reasoning problem requiring control of variables. The task chosen for this investigation was the Mealworm problem.

2 See: Karplus, R., Lawson, A., Wollman, W., Appel, M., Bernoff, R., Howe, A., Rusch, J., & Sullivan, F. Science teaching and the development of reasoning. Berkeley, CA: University of California, 1977.

The task was presented by three methods: (1) individual clinical interview; (2) group presentation of task followed by paper-and-pencil problem with illustration; and (3) group administration of paper-and-pencil instrument with illustration. Each method included four formats: (1) completion answer with essay justification; (2) completion answer with multiplechoice justification; (3) multiple-choice answer with essay justification; and (4) multiple-choice answer with multiple-choice justification. Two hundred and fifty-three (253) students who were enrolled in a freshman level biological science class participated in the study. The research design was a 3 × 4 factorial design with method and format of assessment as the main effects. The participants were in 12 randomly selected laboratory or discussion sections, and each section was randomly assigned to a cell in the research design. Regression analysis with the individual as the unit of analysis showed that format but not method of assessment accounted for a significant amount of variance in student performance. The overall interaction was nonsignificant. Regression analysis with sections as the unit of analysis revealed nonsignificant findings for both method and format. The interrater agreement in the scoring of the Mealworm task was 82.1%. The principal conclusion is that format but not method of task administration influenced the performance of subjects, and the influence is similar for various combinations of method and format. Discussion is focused on the relative importance of the nonsignificant and significant findings for using alternative methods of Piagetian assessment. The results are also discussed with respect to earlier work, and suggestions for future research as well as implications for teachers are set forth.     

The effects of advance organizer and prerequisite knowledge passages on the learning and retention of science concepts

Fifty-five ninth-grade science students participated in this study which compared the effects of two pretreatments, an advance organizer and a prerequisite knowledge passage, on learning and retention measured at low (knowledge and comprehension) and high (application and analysis) levels of the cognitive domain. The effectiveness of the pretreatments was measured by a framework test and a prerequisite knowledge test prior to the beginning of instruction. An analysis of covariance, with IQ as the covariate, was performed on the framework test and the prerequisite knowledge test. It was found that the advance organizer group performed significantly better than the prerequisite knowledge group (p < 0.001) on the first framework test, and the prerequisite knowledge group performed significantly better (p < 0.001) than the advance organizer group on the prerequisite knowledge test. These results provide evidence that both passages were read and understood by the students and that the passages had their intended effects as preinstructional treatments. An analysis of covariance, with IQ as the covariate, was performed on the low-level questions, high-level questions, and total score for the posttest and retention test. The group means for the two question levels and the total score were not found to be significantly different (p > 0.05) for either the posttest or retention test. The results of this study do not provide evidence that an advance organizer facilitates learning and retention more than a preinstructional treatment that concentrates on developing prerequisite knowledge.     

An Exploratory Study of the Effects of Time Compressed Animated Delivery Multimedia Technology on Student Learning in Reproductive Physiology

Two experiments examined the effects of a multimedia technology referred to as “Time Compressed Animated Delivery” (TCAD), on student learning in a junior-level reproductive physiology course. In experiment 1, participating students received one of two presentations of the same instructional material: TCAD and a lecture captured on video. At the completion of each presentation a test was administered and group mean test scores computed and compared. The results were statistically significant (df = 362, t = 10.623, p < 0.05), favoring the TCAD treatment group. The effect size estimate was 1.14. In experiment 2, student learning from three groups were compared on the same reproductive physiology unit used in experiment 1: (1) TCAD, (2) TCAD without the 3-D component, and (3) video-lecture. After removal of three poor functioning items, a one-way analysis of variance was computed. The results were statistically significant (df = 2, F = 2.351, p < 0.10). Results of post hoc comparisons showed that differences in mean test scores between the TCAD and control groups were statistically significant (p < 0.05). The effect size estimate was 0.25. These findings provide preliminary evidence for use of TCAD.     

Prediction/discussion-based learning cycle versus conceptual change text: comparative effects on students’ understanding of genetics

Background and purpose:

The purpose of this study was to investigate the comparative effects of a prediction/discussion-based learning cycle (HPD-LC), conceptual change text (CCT) and traditional instruction on 10th grade students’ understanding of genetics concepts.

Sample:

Participants were 112 10th basic grade male students in three classes of the same school located in an urban area. The three classes taught by the same biology teacher were randomly assigned as a prediction/discussion-based learning cycle class (n?=?39), conceptual change text class (n?=?37) and traditional class (n?=?36).

Design and method:

A quasi-experimental research design of pre-test–post-test non-equivalent control group was adopted. Participants completed the Genetics Concept Test as pre-test–post-test, to examine the effects of instructional strategies on their genetics understanding. Pre-test scores and Test of Logical Thinking scores were used as covariates.

Results:

The analysis of covariance showed a statistically significant difference between the experimental and control groups in the favor of experimental groups after treatment. However, no statistically significant difference between the experimental groups (HPD-LC versus CCT instruction) was found.

Conclusions:

Overall, the findings of this study support the use of the prediction/discussion-based learning cycle and conceptual change text in both research and teaching. The findings may be useful for improving classroom practices in teaching science concepts and for the development of suitable materials promoting students’ understanding of science.     

Exploring halaqah as research method: a tentative approach to developing Islamic research principles within a critical ‘indigenous’ framework

This paper explores a traditional Islamic pedagogy known as halaqah as a potentially useful authentic research method and contributes to discourses about critical and indigenous research methodologies through an analysis of Islamization of Knowledge and other ‘critical indigenous’ movements amongst Muslims. Islamic research principles are tentatively proposed and then used to assess the effectiveness of halaqah as an authentic Islamic research method through analysis of a small qualitative study. The study involved Muslim mother-teachers participating in halaqah to collaboratively reflect on their work as holistic Islamic educators who are developing a ‘critical indigenous’ education to meet the needs of Muslim children in contemporary Britain. This paper argues that halaqah is a more authentic research method in this study than a group interview or focus group as it enabled participants to articulate themselves within their own epistemological and ontological context and engage in critical reflection within an Islamic paradigm.     

Effects of conceptual assignments and conceptual change discussions on students' misconceptions and achievement regarding force and motion

The purpose of this study was to investigate the effects of conceptual assignments and conceptual change discussions on students' achievement and misconceptions about force and motion. The study was conducted with 6 physics teachers and their 18 classes, consisting of 396 high school physics students. The teachers administered the Force Misconception and Force Achievement Tests to their physics classes as a pretest. The results obtained were used to match the 18 classes statistically. Students assigned to the conceptual assignment protocol completed five conceptual assignments about force and motion. Students assigned to the discussion method participated in conceptual change discussions. At the end of the 8‐week treatment period, the same tests were administered to all students as a posttest. The data were analyzed by using multivariate analysis of covariance, followed by protected univariate F test and step‐down analysis. The statistical results showed that the conceptual change discussion was an effective means of reducing the number of misconceptions students held about force and motion. The conceptual change discussion was also found significantly effective in improving students' achievement in force and motion. © 2002 Wiley Periodicals, Inc. J Res Sci Teach 39: 1001–1015, 2002     

Synthesis of Schiff bases of naphtha[1,2-d]thiazol-2-amine and metal complexes of 2-（2＇-hydroxy）benzylideneaminonaphthothiazole as potential antimicrobial agents

Objective： A series of 2-benzylideneaminonaphthothiazoles were designed and synthesized incorporating the lipophilic naphthalene ring to render them more capable of penetrating various biomembranes. Methods： Schiff bases were synthesized by the reaction of naphtha[1,2-d]thiazol-2-amine with various substituted aromatic aldehydes. 2-（2＇-Hydroxy）ben- zylideneaminonaphthothiazole was converted to its Co（Ⅱ）, Ni（Ⅱ） and Cu（Ⅱ） metal complexes upon treatment with metal salts in ethanol. All the compounds were evaluated for their antibacterial activities by paper disc diffusion method with Gram positive Staphylococcus aureus and Staphylococcus epidermidis and Gram negative Escherichia coli and Pseudomonas aeruginosa bacteria. The minimum inhibitory concentrations of all the Schiff bases and metal complexes were determined by agar streak dilution method. Results： All the compounds moderately inhibited the growth of Cram positive and Gram negative bacteria. In the present study among all Schiff bases 2-（2＇-hydroxy）benzylideneaminonaphthothiazole showed maximum inhibitory activity and among metal complexes Cu（Ⅱ） metal complex was found to be most potent. Conclusion： The results obtained validate the hypothesis that Schiff bases having substitution with halogens, hydroxyl group and nitro group at phenyl ring are required for the antibacterial activity while methoxy group at different positions in the aromatic ring has minimal role in the inhibitory activity. The results also indicated that the metal complexes are better antibacterial agents as compared to the Schiff bases.     

Activity optimization method in SPECT： A comparison with ROC analysisActivity optimization method in SPECT： A comparison with ROC analysis

A discriminant method for optimizing activity in nuclear medicine studies is validated by comparison with ROC （received operating characteristic）-curves. The method is tested in 21 single photon emission computerized tomography （SPECT）, performed with a cardiac phantom. Three different lesions （Lb L2 and L3） were placed in the myocardium-wall by pairs fbr each SPECT. Three activities （84, 37 or 18.5 MBq） of 99mTc were used as background. Linear discriminant analysis was used to select the parameters that characterize image quality among the measured variables in the images [（Background-to-Lesion （B/Li） and Signal-to-Noise （S/N） ratios）]. Two clusters with different image quality （P=0.021 ） were obtained. The ratios B/Lj, B/L2 and B/L3 are the parameters used to construct the function with 100% of cases correctly classified into the clusters. The value of 37 MBq was the lowest tested activity for which good results for the B/Li ratios were obtained. The result coincides with the applied ROC-analysis （r=0.89）.     

Storytelling as a democratic approach to data collection: interviewing children about reading

Background Before the 1990s, an individual or medical model dominated educational research methodology with respect to younger children: the subjects of the research were usually considered untrustworthy sources of information. A subsequent shift towards an ecological model has focused on the child's perspective: however, Lewis and Lindsay have described the development of methods for conducting research with children as slow.

Purpose This paper examines how storytelling can be used as a method of collecting authentic and revealing research data from children. The method is suggested as a valuable way in which to gain insights into children's discourse, and is used in this paper in relation to children's discourse about reading.

Sample, design and methods The storytelling method was initially trialled in one school with 36 children aged between 5 and 11 years. The storytelling interview was then used in case studies over a period of a year in three schools, with a total of 88 7- and 8-year-old children. During the interviews, children were asked to tell a story entitled ‘The child who didn't like reading’. Systematic content analysis was undertaken to identify emergent cultural norms and models in the stories. Information on the children's reading practices, and their observations on reading, was also collected for the purposes of triangulation.

Results The children's storytelling gave access to their cultural models of reading. It was found that the stories demonstrated sufficient triangulation with the other data about the children's reading practices to support a sociocultural production of the children's discourse.

Conclusions Storytelling can provide a useful and credible method of collecting research data from children. It may be especially useful with poor readers as there are no literacy demands, and in this respect, affords socially inclusive research.     

Application of near-infrared spectroscopy to predict sweetpotato starch thermal properties and noodle quality

Sweetpotato starch thermal properties and its noodle quality were analyzed using a rapid predictive method based on near-infrared spectroscopy （NIRS）. This method was established based on a total of 93 sweetpotato genotypes with diverse genetic background. Starch samples were scanned by NIRS and analyzed for quality properties by reference methods. Results of statistical modelling indicated that NIRS was reasonably accurate in predicting gelatinization onset temperature （To） （standard error of prediction SEP=2.014 ℃, coefficient of determination RSQ=0.85）, gelatinization peak temperature （Tp） （SEP=-1.371 ℃, RSQ=0.89）, gelatinization temperature range （Tr） （SEP=2.234 ℃, RSQ=0.86）, and cooling resistance （CR） （SEP=0.528, RSQ=0.89）. Gelatinization completion temperature （To）, enthalpy of gelatinization （△H）, cooling loss （CL） and swelling degree （SWD）, were modelled less well with RSQ between 0.63 and 0.84. The present results suggested that the NIRS based method was sufficiently accurate and practical for routine analysis of sweetpotato starch and its noodle quality.