Fen Başarısını Yordayan Özelliklerin Sınıflandırma ve Regresyon Ağacı (SRA) Yöntemiyle Belirlenmesi: TIMSS 2015 Türkiye Örneği

In the current study, it was aimed to determine student, teacher and school characteristics that predict science achievement of eight grade students in Turkey. In the study, the data of TIMMS 2015 were used and the study group was comprised of a total of 6079 students and 220 teachers from 218 different schools. As the data collection tools, the eighth grade science achievement test used in TIMMS 2015 and the scales administered to students and teachers and reflecting student, teacher and school characteristics were used. Since there was a multi-level data structure where students were nested in schools, the created model was analyzed by using the RE-EM algorithm, which enables multi-level data structures to be analyzed through the classification and regression tree (CART) method. The predicted variable of the model was students’ science achievement scores and the predictor variables were the seventeen student, teacher and school characteristics expressed in the scales. According to the results obtained, it was determined that five of the seventeen predictor variables predicted the students’ science achievement, which are students confident in science, student bullying, teaching limited by student needs, school discipline problems and school emphasis on academic success. It has been observed that students who have students confidence in science, level of bullying they are exposed to, emphasis on academic success in their schools, school discipline problems in their schools are more, and whose teachers stated that they have more teaching limited by student needs, are more successful.Çalışmada, Türkiye’de öğrenim gören sekizinci sınıf öğrencilerinin fen başarılarını yordayan öğrenci, öğretmen ve okul niteliklerinin neler olduğunun belirlenmesi amaçlanmıştır. Araştırmada TIMSS 2015 uygulaması verileri kullanılmış olup, araştırmanın çalışma gurubunu bu uygulamaya katılan 218 okuldan 6079 öğrenci ve 220 öğretmen oluşturmuştur. Veri toplama araçları olarak, TIMSS 2015 uygulamasında kullanılan sekizinci sınıf fen başarı testi; öğrenci ve öğretmenlere uygulanan öğrenci, öğretmen ve okul özelliklerini yansıtan ölçekler kullanılmıştır. Öğrencilerin okullar içinde yuvalandığı çok düzeyli veri yapısı söz konusu olduğundan; oluşturulan model, çok düzeyli veri yapılarının sınıflandırma ve regresyon ağacı (SRA) yöntemiyle çözümlenmesini sağlayan RE-EM algoritması aracılığıyla analiz edilmiştir. Modelin yordanan değişkenini öğrencilerin fen başarı puanları; yordayıcı değişkenlerini ise, belirtilen ölçeklerle ifade edilen öğrenci, öğretmen ve okul özelliklerine ait on yedi nitelik oluşturmuştur. Elde edilen sonuçlara göre, on yedi yordayıcı değişkenden beşinin öğrencilerin fen başarısını yordadığı saptanmış olup, bunlar; öğrencilerin öz-yeterliği, zorbalığa maruz kalma, öğrencilerden kaynaklanan sorunlar, okul disiplini ve güvenliği ve okulda başarıya verilen önem şeklinde sıralanmıştır. Öz-yeterlik inancı, maruz kalınan zorbalık düzeyi, okullarında başarıya verilen önem, okullarındaki disiplin ve güvenlik önlemlerinin yüksek olduğu ve öğretmenlerin öğrenciden kaynaklanan sorunları daha yüksek düzeyde nitelendirdikleri öğrencilerin daha başarılı olduğu gözlenmiştir

Investigation of Required Qualifications of Instructors by Means of Pair-wise Comparison Method

AbstractThis study investigates the qualifications instructors should have by using the pair-wise comparison method. The data collection tool included 8 (eight) qualifications regarding students’ demographic data for pair-wise comparison method. Study data were collected from 1241 students from several faculties and departments in 9 Turkish universities. According to the students’ views, motivating to learn is the leading qualification required of instructors. The first qualification on the list was found to differ by gender. Accordingly, female students rated motivating to learn the most, while male students rated being inquisitive. By grade level, first-year students prefer having content knowledge by instructors, whereas second, third and fourth-year students opt for motivating to learn on instructors’ side. As for distribution by faculties; the students from Education Faculty want instructors to motivate to learn, students from Faculty of Science and Letters require beinginquisitive, Faculty of Pharmacy motivating to learn, Faculty of Law prefer democratic instructors, Economic and Administrative Sciences require having world knowledge, Faculty of Aquaculture motivating to learn, and Faculty of Engineering prefer inquisitive instructors. Distribution of the study results by field shows that motivating to learn is the most wanted qualification by students in applied and social sciences, while having good content knowledge by health students.Lastly, a difference was found between newly founded universities and others. The students studying in newly established students mainly require having good content knowledge, whereas others opt for being inquisitive as required qualifications of instructors

PISA Öğrenci Anketinin Kültürler Arası Eşdeğerliği*

In this study, cross-lingual and cross-cultural equivalence of the Programme for International Student Assessment (PISA) 2006 Student Questionnaire was assessed comparatively across Turkey,the United States of America, Australia, and New Zealand samples. At the first stage of this study, thefactor structure of the questionnaire constructs was examined using Confirmatory Factor Analysis(CFA). At the second stage, Multi-Group Confirmatory Factor Analyses (MG-CFA) based on Meanand Covariance Structures (MACS; Sörbom, 1974) were conducted in order to determine whether thequestionnaire items exhibit differential item functioning (DIF) across different cultures or languages.At the last stage, causes of DIF were identified by expert judgments. CFA results showed that themeasurement model had the same factor structure across samples. MG-CFA results indicatedthat some items exhibited DIF between countries. It is observed that as the linguistic and culturaldifferences increased between countries, the number of DIF items increased. The main reasons forDIF were found to be due to poor translation and differences in cultural relevance.Bu araştırmada Uluslararası Öğrenci Değerlendirme Programı (PISA) 2006 kapsamında uygulanan öğrenci anketinin kültürler ve diller arası eşdeğerliği, Avustralya, Yeni Zelanda, AmerikaBirleşik Devletleri ve Türkiye örneklemleri üzerinde karşılaştırmalı olarak incelenmiştir. Araştırmanınbirinci aşamasında, öğrenci anketinin faktör yapısı Doğrulayıcı Faktör Analizi (DFA) yöntemiyleincelenmiştir. İkinci aşamada ise, Ortalama ve Kovaryans Yapıları (OKY; Sörbom, 1974) metodunadayanan Çoklu Grup Doğrulayıcı Faktör Analizi (ÇG-DFA) kullanılarak anket maddelerinin farklıkültürler ve diller arasında Değişen Madde Fonksiyonu (DMF) gösterip göstermediği araştırılmıştır.Son aşamada, uzman görüşlerine başvurularak, maddelerin DMF göstermesinin nedenleribelirlenmeye çalışılmıştır. DFA sonuçları ölçme modelinin tüm örneklemlerde aynı faktör yapısınasahip olduğunu göstermiştir. ÇG-DFA bulguları ülkeler arasında değişen fonksiyon gösterenmaddelerin olduğunu ortaya koymuştur. Ülkeler arasında dilsel ve kültürel farklılıklar arttıkçaDMF gösteren maddelerin sayısının da arttığı gözlenmiştir. Maddelerin DMF göstermesinin asılnedenlerinin çeviri problemleri ve kültürel farklılıklar olduğu sonucuna varılmıştır

PISA 2009 Sonuçlarına Göre Öğrenci Başarısını Etkileyen Faktörlerin Kanonik Ortak Etki Analizi ile İncelenmesi

The aim of this study was to investigate relations between the factors related to Turkish students’ reading abilities and the factors related to facilities that both students and families had, according to PISA 2009 results. The main reason that researchers do not employ canonical correlation analysis to determine relationship between the variables is that interpreting the results are difficult and complex. By calculating unique and common variance associated with variables in each variable sets, canonical commonality analysis helps to determine accurately degree of multicollinearity between the variables, suppressor variable (if there is) and related importance of variables in a canonical model. Thus, it helps researcher make more accurate and reliable interpretation. In this study, predictor variable set consists of factors related to facilities that students and family had and criterion variable set consists of factors related to students’ reading abilities. Relationship between variable sets were investigated with canonical commonality analysis. As a result, predictor and criterion variable sets explained 31.7% of variance in students’ academic success. In addition, according to commonality analysis, utilizing information technologies while preparing homework variable was a suppressor and there was a great multicollinearity between facilities that students had at home and socio-economic status of families variables.Bu çalışmanın amacı PISA 2009 sonuçlarına göre Türk öğrencilerinin okuma becerilerini etkileyen değişkenler ile öğrenci ve ailenin sahip olduğu olanaklara ilişkin değişkenler arasındaki ilişkilerin kanonik ortak-etki analizi ile incelenmesidir. Yapılan çalışmalarda değişken kümeleri arasındaki ilişkiyi incelemede kanonik korelasyon analizinin kullanılmamasının temel sebebi analiz sonuçlarının yorumlanmasının zor olmasıdır. Kanonik ortak-etki analizi her bir değişken kümesindeki değişkenlere ait özgün ve ortak varyanslarını hesaplayarak değişkenler arasındaki çoklu bağlantının derecesini, her bir değişkenin analize olan katkısını hesaplamaya ve baskın (suppressor) değişkenin varlığının belirlenmesine olanak sağlar. Böylece araştırmacının daha doğru ve güvenilir yorumlar yapmasına yardımcı olur. Bu çalışmada öğrencilerin ve ailenin sahip olduğu olanaklar yordayıcı değişken kümesini ve okuma becerileri ile ilişkili faktörler ise ölçüt değişken kümesini oluşturmaktadır. Değişken kümeleri arasındaki ilişki ise kanonik ortak etki analizi ile incelenmiştir. Sonuç olarak, yordayıcı ve ölçüt değişken kümelerindeki değişkenlerin öğrenci başarısındaki varyanasın%31,7’sini açıkladığı bulunmuştur. Ayrıca ortak etki analizi sonucu, öğrencilerin ödev hazırlarken bilişim teknolojilerinden yararlanması değişkeninin baskın değişken olduğu ve öğrencinin evde sahip olduğu olanaklar ile ailenin sosyo-ekonomik düzeyi arasında çoklu bağlantının yüksek olduğu bulunmuştur

Investigation of Two Facets Design With Generalizability In Item Response Modeling

An approach called generalizability in item response modeling (GIRM) is investigated with two facets sx(i: t) design and results are compared with results of generalizability theory in this study. In this study simulated data is used. In Generalizability Theory linear model random facets balanced bx(m: h) design are used for generating data. Generated data are differed by factors. These factors are testlet effect, testlet length and number of testlet. All generated data consist of two different universes and all universes have four different conditions. According to the results of this study the estimates of variance components obtained using GIRM approach are generally quite similar to those obtained using GT approach. Briggs and Wilson's study is supported this result. There is no difference between results of GIRM and GT but error variance could be separated from residual variance with GIRM. This study also examines the reliability of testlets under different conditions. Testlets are more reliable when person-item variance is smaller. Furthermore, when testlet effect is increased, reliability is decreased. When conditions of all universes are investigated it is concluded that it is effective to have more items to increase reliability

Prevalence of sleep disorders in the Turkish adult population epidemiology of sleep study

Sleep disorders constitute an important public health problem. Prevalence of sleep disorders in Turkish adult population was investigated in a nationwide representative sample of 5021 Turkish adults (2598 women and 2423 men, response rate: 91%) by an interviewer‐administered questionnaire. Insomnia was defined by the DSM‐IV criteria, habitual snoring and risk for sleep‐related breathing disorders (SDB) by the Berlin questionnaire, excessive daytime sleepiness (EDS) by the Epworth sleepiness scale score, and restless legs syndrome (RLS) by the complaints according to the International Restless Legs Syndrome Study Group criteria. Mean age of the participants was 40.7 ± 15.1 (range 18 to 90) years. Prevalence rates (men/women) were insomnia 15.3% (10.5%/20.2%; P < 0.001), high probability of SDB 13.7% (11.1%/20.2%; P < 0.001), EDS 5.4% (5.0%/5.7%; P: 0.09), RLS 5.2% (3.0%/7.3%; P < 0.001). Aging and female gender were associated with higher prevalence of sleep disorders except for habitual snoring. Prevalence rates of the sleep disorders among Turkish adults based on the widely used questionnaires were close to the lower end of the previous estimates reported from different parts of the world. These findings would help for the assessment of the health burden of sleep disorders and addressing the risk groups for planning and implementation of health care

İçerik Ağırlıklandırmasının Maddeler-Arası Boyutluluk Modeline Dayalı Çok Boyutlu Bilgisayar Ortamında Bireyselleştirilmiş Test Yöntemleri Üzerindeki Etkisinin İncelenmesi

The purpose of this study is to compare the performance of Between-item dimensionality-based Multidimensional CAT designs and to examine the effect of content balancing on different MCAT designs. For this purpose, real data set obtained from English Proficiency Test (EPT), which was administered by Hacettepe University between 2009 and 2013 academic years, was used. The three dimensional item pool consisted of real items measuring students’ listening, grammar and reading abilities. Item pool consisted of 555 items which was calibrated with 2PL between-item MIRT model. In this study, two different theta estimation (Fisher scoring and Bayesian MAP) methods, three different fisher information based item selection methods (A-optimality, D-optimality and Random) and three different precision based termination methods were used in order to determine the best MCAT design. In addition, results of MCAT algorithms with content distribution and without content distribution were compared so as to examine the effect of content balancing in the context of MCAT. The results of each MCAT condition were compared with respect to, reliability index, SEM, RMSD values associated with each dimension. According to results, both Bayesian MAP and Fisher’s scoring methods yielded similar results when A-Optimality item selection method was used. However, Fisher’s scoring method appeared to be affected from item selection methods and content balancing. Moreover, average number of items tended to increase and reliability coefficients tended to decrease somewhat, while standard error and RMSD values tended to decrease when content balancing was applied in MCAT

Studying reliability of open ended mathematics items according to the classical test theory and generalizability theory

Araştırmada, matematik başarısının ölçülmesiyle elde edilen puanların güvenirliğini belirlemede klasik test kuramı ve genellenebilirlik kuramından yararlanılmıştır. TIMSS- 1999’da yer alan açık uçlu matematik sorularından 24’ü, 2007 yılı bahar döneminde 203 öğrenciye uygulanmıştır. Klasik test kuramına göre elde edilen puanların iç tutarlılığının 0.92 gibi oldukça yüksek bir değer olduğu görülmüştür. Puanlayıcılar arası uyum ise Kendall’ın uyuşum (konkordans) kat sayısı ile belirlenmiş ve 0.52 olarak bulunmuştur. Genellenebilirlik kuramına göre matematik başarısının ölçülmesiyle elde edilen puanların genellenebilirlik kat sayı 0.92 ve güvenirlik kat sayı 0.90 bulunmuştur. Puanlayıcı değişkenlik kaynağının toplam varyansı açıklama oranı % 2,1 olup, oldukça düşüktür. Elde edilen bulgular, kullanılan ölçme aracının, öğrencilerin matematik başarısını belirlemede güvenilir sonuçlar verdiğini göstermektedir. Çalışmada yer alan dört puanlayıcının puan ortalamaları arasında fark olmakla birlikte, birbirleriyle uyumlu puanlama yaptıkları belirlenmiştir.In this study, the Classical test theory and generalizability theory were used for determination to reliability of scores obtained from measurement tool of mathematics success. 24 open-ended mathematics question of the TIMSS-1999 was applied to 203 students in 2007-spring semester. Internal consistency of scores was found as 0.92. For determination of interrater consistency, Kendall’s concordance coefficient was calculated as 0.52. Generalizability coefficient for mathematics scores was 0.92 and phi coefficient was 0.90. The variance component of raters accounted for 2.1% of the total variance. According to all results, it was seen that measurement tool of mathematics success was reliable for determination of students’ mathematics success. Although there was a difference between means of four raters’ scores, it was found that there was consistency of their scores