Browsing by Subject "Meta-analysis"
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Item A quasi meta-analysis of the journal articles in the area of deafblind communication from 1995 to 1999(Texas Tech University, 2000-05) Edmonds, Amy RThe purpose of this study was to analyze the journal articles found between the years 1995 and 1999 in the area of deafblind communication. The method used for this analysis was a quasi meta-analysis. A total of 33 articles were identified from a combination of both on-line database searches and manual searches of selected journals. Each retrieved article was analyzed using a protocol, which specifically identifies author name, number of authors, source of the article, publication year, research design, author affiliation, and communication mode researched. The findings concluded that the field of deafblindness, during these years, focused upon qualitative research, generated from universities with more than one author or researcher. The journals in the area of visual impairment and blindness published the majority of this research. Tactual sign, gestures, sign, and Braille were the communication modes that articles most commonly researched.Item Bayesian Semiparametric Models for Heterogeneous Cross-platform Differential Gene Expression(2012-02-14) Dhavala, Soma SekharWe are concerned with testing for differential expression and consider three different aspects of such testing procedures. First, we develop an exact ANOVA type model for discrete gene expression data, produced by technologies such as a Massively Parallel Signature Sequencing (MPSS), Serial Analysis of Gene Expression (SAGE) or other next generation sequencing technologies. We adopt two Bayesian hierarchical models?one parametric and the other semiparametric with a Dirichlet process prior that has the ability to borrow strength across related signatures, where a signature is a specific arrangement of the nucleotides. We utilize the discreteness of the Dirichlet process prior to cluster signatures that exhibit similar differential expression profiles. Tests for differential expression are carried out using non-parametric approaches, while controlling the false discovery rate. Next, we consider ways to combine expression data from different studies, possibly produced by different technologies resulting in mixed type responses, such as Microarrays and MPSS. Depending on the technology, the expression data can be continuous or discrete and can have different technology dependent noise characteristics. Adding to the difficulty, genes can have an arbitrary correlation structure both within and across studies. Performing several hypothesis tests for differential expression could also lead to false discoveries. We propose to address all the above challenges using a Hierarchical Dirichlet process with a spike-and-slab base prior on the random effects, while smoothing splines model the unknown link functions that map different technology dependent manifestations to latent processes upon which inference is based. Finally, we propose an algorithm for controlling different error measures in a Bayesian multiple testing under generic loss functions, including the widely used uniform loss function. We do not make any specific assumptions about the underlying probability model but require that indicator variables for the individual hypotheses are available as a component of the inference. Given this information, we recast multiple hypothesis testing as a combinatorial optimization problem and in particular, the 0-1 knapsack problem which can be solved efficiently using a variety of algorithms, both approximate and exact in nature.Item Detecting and correcting publication bias in meta-analysis(2009-12) Li, Xin; Borich, Gary D.; Beretvas, Susan NatashaPublication bias (PB) makes the resources for meta-analysis (M-A) unreliable in the sense of completion and accuracy, so to investigate, identify and correct PB is a very important issue in M-A. The current study proposed an empirical comparison in both detection and correcting PB, using a Monte Carlo study. Conditions to be manipulated include the number of primary studies, number of missing studies and true effect size. RANNOR in SAS will be used to generate normally distributed random variables and, for each condition, 10,000 M-As will be simulated. Type I error rates are to be calculated for the conditions with no PB and powers were estimated for the conditions with PB and adequate type I error control. Finally, a demonstration of how M-A can and should be used as a part of program evaluations was given.Item Deviation from panmixia via assortative mating and divergent habitat preferences(2014-12) Jiang, Yuexin, Ph. D.; Bolnick, Daniel; Kirkpatrick, Mark, 1956-; Singer, Michael; DeAngelis, Donald; Leibold, MathewThe speciation process is often viewed to start from panmictic populations. Understanding the evolutionary mechanisms that cause populations to deviate from panmixia is essential to understanding the initial stage of population divergence that may lead to speciation. My dissertation focuses on the evolution of two mechanisms that cause deviation from panmixia: assortative mating and divergent habitat preferences. The first chapter is a meta-analysis on published measures of the strength of assortative mating within natural animal populations. Results showed that deviation from panmixia via weak positive assortative mating was typical within natural animal populations, while disassortative mating was rare or absent. Results also suggested that assortative mating did not typically evolve adaptively, but instead as an incidental consequence of other mechanisms, such as spatial segregation. Divergent habitat uses are important drivers of spatial segregation. The second chapter revealed a behavioral mechanism of divergent habitat uses between parapatric lake and stream threespine stickleback populations. The results showed strong divergent rheotaxis between lake and stream fish during their breeding season. The divergence is likely to contribute to the sorting of lake and stream fish into their natal habitats and promote habitat-based assortative mating. The third chapter focused on the neuroanatomical and morphological mechanisms of rheotaxis. Results showed significant correlations between the numbers of neuromasts (functional units of the lateral line) and rheotaxis in both lab-reared and wild-caught threespine stickleback. Results also showed heritable divergence in lateral line structure between parapatric lake and stream stickleback, suggesting that divergent rheotaxis and the resulting divergent habitat uses are likely to have a heritable component. In summary, my dissertation revealed ultimate evolutionary mechanisms of assortative mating and proximate evolutionary mechanisms of divergent habitat uses. These results shed light on the understanding of the beginning of population divergence and ultimately speciation.Item The effect of negative feedback on motivation : a meta-analytic investigation(2014-05) Fong, Carlton Jing; Patall, Erika A.Although the most prominent view in psychological theory has been that negative feedback should generally have a detrimental impact on motivation, competing perspectives and caveats on this prominent view have suggested that negative feedback may sometimes have neutral or even positive effects on motivation. A meta-analysis of 79 studies examined the effect of negative feedback on motivation and related outcomes with both child and adult samples. Results indicated that negative feedback compared to positive feedback decreased intrinsic motivation and perceived competence. This effect is much smaller when compared to neutral or no feedback. Moderator tests revealed that the effect of negative feedback seems to be less demotivating when a) the feedback statement includes instructional details to improve, b) compared to objective versus normative standards, and c) the task is interesting. Implications for future research and applications to real-world settings are discussed.Item The effect of situated learning on knowledge transfer of students with and without disabilities in inclusive classrooms : a meta-analysis(2012) Kim, Jiyoung; Rieth, Herbert J.The purpose of this meta-analysis was to examine the effect of situated learning on the academic performance of students with and without disabilities in inclusive general education classrooms. While previous research has reported the overall effectiveness of situated learning, relatively few studies have been conducted to investigate how situated learning influences students' academic performances in inclusive settings where students with and without disabilities work together. Moreover, although the main interest of situated learning is about how to apply basic knowledge and skills to an authentic context and, beyond this, how to transfer them into a similar but novel situation in everyday life, little has been known about its effectiveness on students' achievement in terms of knowledge transfer. In this study, a meta-analytical statistical method was employed to investigate the effect of situated learning, and its effectiveness was examined according to the three levels of knowledge transfer (knowledge acquisition, application, and transfer). A total of 19 situated-learning studies, both published and unpublished, were analyzed. Each primary study's effect sizes were calculated using Hedges' g with the bias correction and then combined into the three weighted average effect sizes regarding the levels of knowledge transfer. This meta-analytic study found that, on all of the levels of knowledge transfer, the situated learning is effective for the learning of students with and without disabilities in inclusive general education classrooms. In the random effects model, the situated instruction produced a weighted mean effect size estimate of 2.049 for knowledge acquisition, 1.836 for knowledge application, 1.185 for knowledge transfer. In addition, the percentage of students with special needs in general education classrooms had a negative influence on the effectiveness of situated learning. However, the pattern of results also showed that the proportion of students with special needs in general education classrooms does not influence as greatly the learning of knowledge transfer as it does knowledge acquisition or application.Item Effect Size and Moderators of Effects for Token Economy Interventions(2012-02-14) Soares, DeniseThere is a clear call to use evidence-based practice (EBP) in schools, and a growing knowledge base of practices that have proven to be effective in helping students achieve in educational settings. In addition, the current trends of Positive Behavior Supports (PBS) and Response to Intervention (RtI) advocate for preventative and proactive strategies. Token economies (TE) are one intervention that is proactive and can be flexible to use with students across a wide range of behaviors and settings. According to Higgins, Williams, and McLaughlin, token economy (TE) is an effective way to improve classroom behavior. Unfortunately, limited recent research is available that evaluated the effects and moderators of token economies in classroom settings. The purpose of this investigation was to Meta-analyze the single case research on TE implemented in school and is the first to offer effect size analysis and identify moderators. The use of TE's has been widely established as an evidence-based intervention for use in prisons, psychiatric hospitals, and school settings. However, very few articles discuss size of effects to expect, the essential elements required, or the practical implementation issues within a classroom. Many myths surround the use of a TE, i.e., many assume a token system is effective only for individuals and this is not so, as TE is effective for groups as well as individuals. In an age of accountability and emphasis on preventative evidence based practice evidence for using a TE and how to implement a TE is needed in our literature. Empirical evidence for the use of a token economy in a classroom is presented along with suggested implementation ideas. Twenty four studies were included in this Meta-analysis with an overall combined Tau-U ES of .78 of data showing improvement between phase A and B with CI90 [.72, .83]. Tau-U effect sizes ranged from .35 to 1.0. TE is effective with all ages evaluated (ages 3 - 15); however, statistically significant results indicated it was more effective with ages 6 - 15. Active ingredients (i.e. procedural steps) were evaluated, combined, and reported. Results indicate that TE is an evidence-based intervention to increase academic readiness behaviors and to decrease inappropriate behaviors.Item Investigating Place-based Pedagogy Utilizations In Curricular Practices(2012-02-14) Brown, NikeithaOutlets for students to develop mathematical ideas and skills to solve real-life problems and applicable situations have been neglected in secondary classrooms (Gainsburg, 2008). Designing curricula that applies real-life situations has been promoted by the National Council of Teachers of Mathematics (2000), the National Research Council (1998), and the Commission on Behavioral and Social Sciences and Education (2000) and also is an expectation of state standards for student learning (Texas Education Agency, 2009). Contrary, evidence has shown low benefits to classroom real-life examples perceived by students. This study served dual purposes: 1) Determine the relationship between place-based education and mathematics learning, and 2) Investigate teacher conceptions of place-based education opportunities in high school, mathematics curriculum. This study employed two methodologies. A mixed-methods approach was employed for the meta-analysis of place-based programs and the second employed qualitative methods of structured interviewing to determine teachers? conceptions of place-based pedagogy. Upon completion of the study, I concluded: 1) Place-based pedagogies align toward more foundational mathematic skills (e.g. measurement, number sense) when implemented, and 2) Teachers? conceive place-based as a general effective tool for student engagement and real-world context of how mathematics functions in society.Item A meta-analysis of online trust : examining main and moderating effects(2015-05) Kim, Yeolib; Bias, Randolph G.; Peterson, Robert A. (Robert Allen), 1944-; Westbrook, Lynn; Fleischmann, Kenneth R.; Jarvenpaa, Sirkka L.The purpose of this study was (1) to conduct a meta-analysis on the antecedents and consequences of online trust; (2) to test for seven moderating variables involving online trust; and (3) to use the pooled correlation matrix to fit the research model. The data for the meta-analytic procedure involved 120 papers reporting 150 independent studies. Results showed statistically significant relationships involving online trust and its various antecedents (e.g., perceived security) and consequences (e.g., behavioral intention). The relationships were heterogeneous across studies and the variances for the reported effect sizes were partially explained by certain methodological characteristics. The meta-analytic structural equation modeling analysis indicated that online trust mediates the effect of various antecedents on behavioral intention. A discussion of results, implications, limitations, and future research is provided.Item Meta-analytic methods of pooling correlation matrices for structural equation modeling under different patterns of missing data(2003) Furlow, Carolyn Florence; Beretvas, Susan NatashaThis study compared the effects of different methods of synthesizing correlations for meta-analytic structural equation modeling (SEM) under various patterns of missingness on the estimation of correlation parameters and the resulting SEM parameters and fit indices. Univariate weighting methods for synthesizing correlations are frequently used. An alternative multivariate method for pooling correlation matrices involves using generalized least squares (GLS), where the dependencies of the correlations within the same matrix are taken into consideration (Becker, 1992). Since previous research has reported poor performance with GLS versus univariate weighting procedures, a revised GLS method, W-COV GLS, was used. Both the W-COV GLS procedure and univariate weighting were compared using correlations transformed with Fisher’s z versus untransformed correlations. There is frequently a problem when synthesizing correlation matrices due to the effects of missing data. One type of missing data scenario is the file-drawer problem (Rosenthal, 1979) in which a potential selection bias may occur whereby correlations that are non-significant are not reported. The performance of the different synthesis methods were assessed under different degrees and types of missingness including an approximation of the file-drawer problem using listwise and pairwise deletion to handle missing data. Results from this study indicated comparable performance of univariate weighting with the z transformation and W-COV GLS procedures, both with and without the transformation, for estimating the correlation parameters and ensuing parameters of the structural model. However, the W-COV GLS procedure performed slightly better in estimating the standard errors of the paths in the structural model and for the chi-squared test of data-model fit. When data were MCAR then there was almost no relative bias detected but when data were MNAR there were unacceptably high levels of relative bias in estimation of the correlation and SEM model parameters as well as high model rejection rates regardless of method used to synthesize correlations. Pairwise deletion resulted in higher incorrect rejection rates and larger bias in the standard error estimates for the SEM model than did listwise deletion. Inaccurate standard error estimates were found for several of the paths and attributed to the use of a correlation matrix with SEM.Item A Monte Carlo investigation of multilevel modeling in meta-analysis of single-subject research data(2011-08) Mulloy, Austin Madison; Beretvas, Susan Natasha; O'Reilly, Mark F.; Zuna, Nina I.; Falcomata, Terry; Pituch, KeenanMultilevel modeling represents a potentially viable method for meta-analyzing single-subject research, but questions remain concerning its methodological properties with regard to characteristics of single-subject data. For this dissertation, Monte Carlo methods were used to investigate the properties of a 3 level model (i.e., with a quadratic equation at level 1), and three different level 1 error specifications (i.e., different variance components and covariances of 0, lag-1 autoregressive covariance structures, and separate error terms for each phase, with different variance components and covariances of 0). Data for simulated subjects were generated to have characteristics typical of published single-subject data (e.g., typical variances and magnitudes of effect). Samples were simulated for conditions which varied in number of data points per phase, number of subjects per study, number of studies meta-analyzed, level of autocorrelation in residuals, and continuity of variance across phases. Outcome variables examined included rates of convergence of analyses, power for statistical tests of fixed effects, and relative parameter bias of estimates of fixed effects, random effects’ variance components, and autocorrelation estimates. Convergence rates were found to be 100% for all level 1 error specifications and data conditions. Power for statistical tests of fixed effects was observed to be adequate when 10 or more data points were generated per phase and 60 or more total subjects were included in meta-analyses. The relative biases of estimates of fixed effects were found to have limited associations with numbers of data points per phase, levels of autocorrelation, and the continuity/discontinuity of variance across phases. Random effects’ variance components were observed to be frequently biased. Associations between relative bias and data conditions were found to vary by random effect. Finally, autocorrelation estimates were found to be biased in all conditions for which autocorrelation was generated. Results are discussed with regard to study strengths and limitations, and their implications for the meta-analysis of single subject data and primary single subject research.Item Multivariate GLS meta-analysis on ambient air pollution and congenital heart anomalies(2014-05) Wang, Ni; Beretvas, Susan NatashaThe effects of air pollutants CO, NO₂, O₃, PM₁₀ and SO₂ on congenital heart anomalies are represented by the odds ratio of each disease per unit increase in the concentration of each pollutant. In this study, the effects of air pollutants are summarized using multivariate GLS approach with correlation between outcomes being taken into account, where the correlations are sampled from uniform [-1,1]. Meta-analysis conducted here found no statistically significant increase in odds ratio of any disease. This result is different from what Vrijheid et al. 2011 suggested when correlation is not considered using the same set of data. The difference in conclusions from the two meta-analysis indicate that correlation between outcomes may play an important role when synthesizing effect sizes. Thus, before conduct meta-analysis, a thorough consideration about whether to incorporate the correlation in synthesizing should be given.Item Parent autonomy support, academic achievement and psychosocial functioning : a meta-analysis of research(2014-05) Crowther, Ariana Christine; Borich, Gary D.In a synthesis of research on parent autonomy support, meta-analytic results indicated that parental autonomy support was related to greater academic achievement, autonomous motivation, and psychological health. A meta-analysis of 20 studies correlating parent autonomy support and achievement-related outcomes revealed that parental autonomy support had a positive relationship with achievement outcomes. A meta-analysis of 8 samples from 6 studies correlating parent autonomy support and autonomous motivation revealed autonomy support had a stronger relation with motivation for school in general than motivation for non-school domains. A meta-analysis of 11 studies correlating parent autonomy support and well-being revealed that parental autonomy support had a stronger relation with non-school related self-esteem than in academic self-esteem. Implications for future research and practice are discussed. A suggested intervention program is also analyzed.Item Structured-interview questions for superintendent hiring process(Texas Tech University, 2004-05) Mills, G. SteveThis study contains two distinct parts. The first part of the study is an original study dealing with the development of interview questions that school board members can ask in the superintendent/school board members candidate interview. There is continual superintendent turnover, and school board members choose superintendents based on personal characteristics rather than on a candidate's abilities to lead a district to exemplary status on the Texas Education Agency's accountability system. Therefore, there is a need for interview questions to be used by school board members to help them select a superintendent who will help lead the district to exemplary status on the Texas Education Agency's accountability system. Action Research using the Delphi Method for data collection is used to guide experts in the creation of interview questions to be used by school board members in the superintendent/school board members candidate interview. This part of the study is qualitative in nature. The second part of this study is a replication for generalizability of the characteristics and career paths of national superintendents (Glass et al., 2000) and state superintendents (Largent, 2001; Zemlicka, 2001) as compared to superintendents whose districts reached exemplary status on the Texas Education Agency's accountability system Spring, 2002. This part of the stijdy is both quantitative and qualitative in nature. A survey approach is used to collect data from the 149 superintendents whose districts reached exemplary status on the Texas Education Agency's accountability system Spring, 2002. Open-ended survey questions are presented in a qualitative manner, and closed survey questions are presented in a quantitative manner. The purpose of replicating these prior studies is to emphasize, first, that school board members across all three groups of superintendents hire superintendents based on their personalities, and second, that superintendents in all three groups have some generalizable personal characteristics and career paths. This researcher attempts to fill the gap between the reality of the way superintendents are currently hired and how they might be hired if, first, school board members have a reliable, valid, and legal set of interview questions to ask superintendent candidates and, second, if school board members apply the abundant research available in the area of structured-panel interviews.Item The effect of drama-based instruction on PreK - 16 outcomes : a meta-analysis of research from 1985-2012(2013-05) Lee, Bridget Nicole, 1975-; Patall, Erika A.; Svinicki, Marilla; Cawthon, Stephanie; Hasty, Brent; Bentley-Edwards, KeishaIn May 2011, the President’s Committee on the Arts and Humanities (PCAH) released their report, “Reinvesting in Arts Education: Winning America’s Future through Creative Schools.” The PCAH heartily supported arts integration as an effective and cost efficient way to address teachers’ and students’ needs, referring to arts integration as “the most significant innovation in the field over the last two decades…” (2011). In the report, however, the PCAH called for a better understanding of the dimensions of quality and best practices—when, for whom, and what content areas are best served by arts integration methods. They called for research to clarify evidence on arts integration, not only as it relates to math and English standards but also as it relates to essential 21st century skills: creativity, critical thinking and collaboration (Partnership for 21st Century Skills, 2009). One promising arts integration method is drama-based instruction. In the last twenty-five years, there have been numerous research studies assessing the effectiveness of integrating drama-based strategies into academic curriculum. However, we still do not have a clear idea of the overall effectiveness of drama-based instructional strategies and, maybe more important, the conditions under which it is more or less effective. Prior research, including meta-analyses, have produced mixed results. Four previous meta-analyses found contradictory results and drew differing conclusions about moderators including gender and age. Much research has been published since the earlier meta-analyses. This, along with the need to clarify the effectiveness of DBI, warrants an updated review. An initial search of the literature revealed 45 relevant studies since 1985, suggesting that there is indeed sufficient data to support an updated meta-analysis on the effectiveness of drama-based instruction for enhancing student academic achievement and other adaptive academic and social outcomes. The purpose of this meta-analysis is to provide a nuanced understanding of a specific arts integration method—drama-based instruction—and provide critical insight for practitioners regarding how it may be most profitably used in the classroom to benefit students.Item The Effects Of Closure-Based Multiple Testing On The Power Of P-Value Combination Tests(2011-08) Henning, Kevin; Westfall, Peter H.; Conover, William J.; Mansouri, Hossein; Surles, JamesA multiple testing situation arises whenever several statistical inferences (tests or intervals, although we focus on the former) are considered simultaneously, and the goal is to make valid conclusions about each inference in the presence of the others. Many diverse approaches to dealing with the multiple testing issue, from both the frequentist and Bayesian perspectives, have been proposed, although in this dissertation, we restrict our attention to frequentist hypothesis testing. One increasingly popular procedure for multiple testing is known as the "closure method," or simply "closure." The method allows simultaneous conclusions to be made about individual hypotheses by guaranteeing that the probability of rejecting any true null hypothesis is no greater than α. The method works by testing all subset hypotheses formed by considering the set of all non-empty intersections of the individual hypotheses. To reject an individual hypothesis H_{i} requires rejecting all intersection hypotheses that involve H_{i} . Notably, any test that controls the Type I error rate at level α can be used for these intersection hypotheses, which makes the method quite general. In this dissertation, we consider the power properties of a class of tests known as p-value combination tests (PVCTs) when these tests are used in the closure setting. We consider three types of PVCT that use p-value information differently: additive combination (AC) methods, minimum-p-value (MINP) methods, and one "hybrid" approach, the Truncated Product Method (TPM). We find through simulation studies that the power properties for PVCTs as tests of intersection hypotheses do not carry over when these tests are used in the closure setting. Specifically, the AC and TPM tests generally have higher power than MINP methods as global tests, but much less power than MINP tests in the closure setting (however, we show that the TPM can be modified to perform similarly to the MINP tests by decreasing the truncation level τ as the number of tests increases). Underlying the poor performance of AC methods in closure is the hierarchical nature of closed testing, and we give details on how these "hurdles" cause the dramatic power losses we have observed.Item The effects of vocabulary instruction on English language learners(Texas Tech University, 2008-05) Won, Mijin; Janisch, Carole; Burley, Hansel E.; Akrofi, AmmaThe effectiveness of vocabulary instruction for first language learners has been reviewed in several studies (Petty, Herold, & Stoll, 1968; Stahl & Fairbanks, 1986; National Reading Panel, 2000). However, the reviews of vocabulary instruction research focusing on learners of English as a second (ESL) or foreign language (EFL) are fewer in number. Because empirical research has explored more fully which vocabulary instruction is more useful for learning English vocabulary, there is a need for a study reviewing the results of research related to ESL or EFL students. Many empirical studies measured the effectiveness of some instruction individually in particular cases. Therefore, each instructional approach needs to be examined, reviewed, and integrated to determine the effectiveness as a whole. The findings will have implications for teaching vocabulary to ESL or EFL students. With the above purpose in mind, the following research questions guided my study. Each will be answered by integrating previous studies in this meta-analysis. 1. How can vocabulary instruction for English language learners used in quasi-experimental or experimental studies be categorized? 2. To what degree are these instructional methods effective? What are the effects of such methods on learning vocabulary for English language learners¡¯ achievement? 3. Under what conditions are these kinds of instruction effective? That is, what are the mediating effects of substantive variables affecting vocabulary instruction, such as the age of samples, their levels of English, geographical location, and the publication source of study? To review these various instructional methods with lesser bias and greater validity than the traditional review, a meta-analysis was conducted. Using meta-analysis techniques, the research relating to vocabulary instruction for English language learners was synthesized. Meta-analysis uses effect size as a common metric for comparing outcomes of each experimental or quasi-experimental study. The meta-analytic process has five basic phases (Glass, 1976): (1) formulating the problem, (2) collecting the data, (3) evaluating the data, (4) synthesizing the data and (5) presenting the findings. The categorization of vocabulary instructional studies indicated the variety of instructional approaches studied in the past three decades. Studies were categorized as contextualized instruction, semi-contextualized instruction, or decontextualized instruction. The three categories of studies were divided by multimedia and non- multimedia. The category of studies used multimedia as a teaching tool measured computer-related learning word programs. These computer programs were subcategorized as to whether they used first language supports in the programs. The overall effect size was d=.69 for this meta-analysis. Since the effect size is the same as a z score, an effect size .7 is the same as .2580 (about 26%). This means that if the control groups were to receive the treatment, their scores should improve about 26% on the average. Even though all of the instruction is effective for English language learners, decontextualizing instruction is the most effective for them. Decontextualizing instruction is focusing on the word meaning separately from context with a flash card or word list, or any other activities that focus on forms or core meanings of words. Contextual instruction shows the lowest effect size than the other two types of instruction. The study indicates there are no different effects of vocabulary instruction on learning condition between ESL and EFL. The use of multimedia in vocabulary instruction was found to be more effective than control groups, but the effect size of multimedia groups was lower than the group without multimedia use. Therefore, it could be said that the use of a computer is not better than a classroom teacher. Although there are debates on the effectiveness of first language use for second language learners, the results of this study yielded no differences with or without first language supports, unless the instruction was associated with the other specific factors. This meta-analysis confirms that vocabulary instruction for ESL or EFL learners has some similarities and dissimilarities to that of first language learners. To determine more effective instruction for EFL or ESL learners, a consideration of the characteristics of learners and environments as well as instructional approaches should be made. From this study, it was concluded that effective instruction for English language learners depends on the conditions of vocabulary instruction. ESL and EFL classroom teachers need to consider the difference depends on the conditions of vocabulary instruction. ESL and EFL classroom teachers need to consider the differences of first and second language vocabulary acquisition as well as student learner characteristics.Item Understanding cyberbullying in the net generation: A meta-analytic review(2012-12) Oblad, Tim; Reifman, Alan; Trejos-Castillo, Elizabeth; Bell, Nancy J.The world over has seen an increase in technological expansion. Adolescents are active consumers in the spread of social networking sites and interfacing online. Though there are many benefits for Internet and communication technologies, there are also numerous concerns for a new issue: Cyberbullying. Defined as bullying through electronic communication (Li, 2008) or any hostile or aggressive message sent digitally and repeatedly to an individual (Tokunaga, 2010), Cyberbullying is a new type of bullying receiving media attention as a new world epidemic by increasing frequency of online bullying, suicides, threats, and legal action. Particularly in the case of a fast growing global phenomenon like cyberbullying, research is necessary to better understand the implications for individuals across contexts, and to develop a cohesive groundwork for researchers and policy makers to draw upon. In the current study, a comprehensive review of literature throughout the world over the last decade on cyberaggression identifies a multitude of terminologies used by individual countries; for example, electronic bullying in the US may be understood in Germany as cyber-mobbing, in Italy as Virtual-bullying, or the Czech Republic as online harassment (Kowalski & Limber, 2007; Nocentini et al. 2010; Ševčíková, & Šmahel; 2009). Also, definitional issues such as what qualifies as cyberbullying and if cyberaggression (Grigg, 2010) is a more appropriate definition to grasp the nature of cyberbullying behaviors. Behavioral patterns of cyberbullies and victims regarding platform, or type of media preferred was found by reviewing 95 articles. Countries were grouped into North America (NA) and the rest of the world, which includes Europe, Asia, and Australia (EAA) as the other group for comparison. In NA, chatrooms were the most common platform for bullies and victims. EAA reported Internet use (unspecified means). This study also identified most common responses or reasons cyberbullies act aggressively towards others online. Most common responses in NA were because of previous victimization; the EAA group reported a tie between pro-social issues/empathy and high frequency online. From meta-analyses, gender differences show males to be more involved with cyberbullying than females, whereas females are cybervictimized more than males. These findings support and contradict current research as females were thought to be more involved with relational aggression (Archer & Coyne, 2005) than males. Recommendations for future research and implications of findings are discussed.