The Use of Split Exponential and Split Weibull Analyse Survival Data With Long Term Survivors

The split population model is a flexible way of extending the standard survival analytical methods to failure time data in which susceptibles and long-term survivors coexist. Susceptibles would develop the event with certainty if complete follow-up were possible, but the long-term survivors would never experience the event. A study was conducted to allow the effects of covariates on the probability that an individual is immune, and the immune probability vary from individual to individual. In effect, we are associating with each individual a distinct probability of being immune, which depends on the covariate information specific to that individual. And then fitted a few models using the maximum likelihood estimation to determine whether the covariates are significant or not. Several popular distributions on the survival data analysis as endorsed by graphical techniques were used. We applied the split exponential and the split Weibull models together with deviance test, a parametric test for the presence of immunes, and a test for outlier, to test for sufficient follow-up in the samples where there may or may not be immunes presences. We presented the probability of eventual immune for the ith individual as the logit model and logistic model. We will work with two data sets, firstly a Clinical Trial in the Treatment of Carcinoma of the Oropharynx and secondly Stanford Heart Transplant data. The results from the data analyses for a Clinical Trial in the Treatment of Carcinoma of the Oropharynx data show that the simple exponential model produces a fit not significantly worse than the simple Weibull model and the simple split Weibull model no better than the simple split exponential model, also shown that no evidence of immune population and all covariates are not significant. The results from the data analyses for Stanford Heart Transplant data show that the simple Weibull model is significantly better than the simple exponential model, and the simple split Weibull model is better than the simple split exponential model. We have calculated the maximum log-likelihood function value for both the logit exponential and logistic exponential models. They are exactly similar for both the Clinical Trial in the Treatment of Carcinoma of the Oropharynx and Stanford Heart Transplant data. So, we suggest that both the logit exponential and logistic exponential models are equally superior

A COMPARISON OF STUDENTS SELF-BELIEF AND MATHEMATICS ACHIEVEMENT IN THE ASIAN COUNTRIES: FINDING FROM THE THIRD INTERNATIONAL MATHEMATICS AND SCIENCE STUDY (TIMSS)

The Trends in Mathematics and Science Study (TIMSS) is an international assessment of fourth and eighth grade students achievement in mathematics and science. The purpose of this study was examine the compares of student self- belief and mathematics in Asian countries using data from the Third International Mathematics and Science Study 2011. The analysis is conducted through a Multivariate Analysis of Variance (MANOVA) model with random effects for each country. East Asian countries Korea, Singapore, and Chinese Taipei Hong Kong SAR and Japan were the top-performing countries at the eighth grade to lead the world in mathematics achievement. The null hypotheses used in this study there are no statistically significant difference in self belief and mathematics achievement between Asian students

Penggunaan Perangkat Pembelajaran Geometri Ruang Berbasis Ict untuk Meningkatkan Kemampuan Berpikir Tingkat Tinggi Mahasiswa

Pembelajaran geometri ruang merupakan salah satu pembelajran yang memerlukan kemampuan analitis dan komunikatif mahasiswa. Tujuan penelitian ini adalah 1) untuk mengkaji penggunaan perangkat pembelajaran geometri ruang berbasis ICT dalam meningkatkan kemampuan berpikir tingkat tinggi, 2) untuk mengetahui respon mahasiswa terhadap penggunaan perangkat pembelajaran geometri berbasis ICT. Pembelajaran geometri memerlukan kemampuan mengkomunikasikan bangun yang sifatnya abstrak menjadi konkrit sehingga dapat meningkatkan kemampuan berpikir tingkat tinggi dengan menggunakan ICT. Hasil kajian ini menunjukkan perangkat pembelajaran berbasis ICT dengan program wingeom dapat meningkatkan kemampuan berpikir tingkat tinggi. Learning geometry of space is one pembelajran that require analytical and communicative abilities of students. The purpose of this study were 1) to assess the use of the learning device geometry of space-based ICT in enhancing the ability to think critically, 2) to study the response of students to use ICT-based learning device geometry. Learning geometry requires the ability to communicate wake which is abstract into the concrete so as to increase high-level thinking skills by using ICT. Results from this study indicate the ICT-based learning with wingeom programs can increase high-level thinking skills

STUDENTS’ MISCONCEPTIONS IN INTERPRETING THE MEAN OF THE DATA PRESENTED IN A BAR GRAPH

Interpreting the mean of the data presented in a bar graph constitutes a mix of two concepts highly useful for testing students’ level of understanding of the mean. This study aimed to  describe students’ misconceptions in the interpretation of the mean of data that are represented in a bar graph and the causes of such misconceptions and to examine whether misconceptions differed by gender and grade. The participants of this study consisted of 112 students (48 males, 64 females) of the Natural Science program of SMAN 1 Tanjungpinang in three grades—tenth, eleventh, twelfth. Employing a mixed method with an exploratory sequential design, this study collected and analyzed qualitative data prior to quantitative ones. The research identified 12 misconceptions about the mean and 8 causes of such misconceptions, and based on the chi-squared test results, neither gender- nor grade-based difference in students’ misconceptions was found. These results have an implication for teachers and other educational stakeholders in considering the achievement of learning objectives and core competences in the learning process, especially in the processing, reasoning, and presentation of the mean of data that are presented in a bar graph

Analisis Kesulitan Siswa Dalam Menyelesaikan Soal Pemecahan Masalah Matematis Ditinjau Dari Gaya Belajar Siswa SMA Kelas XI

Penelitian mempunyai tujuan untuk mendeskripsikan  kesulitan yang dialami siswa dalam menyelesaikan soal pemecahan masalah matematis ditinjau dari gaya belajar visual, auditorial, dan kinestetik. Peneliti ini memakai jenis kualitatif bersifat studi kasus. Guna memperoleh nilai, riset memakai teknis angket, tes, serta wawancara. Untuk menganalisis data, peneliti melakukan reduksi data, sajian data, dan penarikan kesimpulan. Hasil analisa data, Siswa dengan gaya belajar visual  mendapat kesulitan menyelesaikan soal pemecahan masalah matematis dengan 3 indikator. Siswa dengan gaya belajar auditorial mengalami kesulitan saamenjawab soal pemecahan masalah matematis dengan 4 indikator. Siswa dengan gaya belajar kinestetik mendapat kesulitan dalam menyelesaikan soal pemecahan masalah matematis dengan 2 indikator.

ANALISIS PENGGUNAAN VISUAL MEDIATOR KETIKA MAHASISWA MELAKUKAN PENALARAN STATISTIS

Abstrak  Visual mediator dapat digunakan sebagai alat bantu berpikir dalam wacana matematika, dan merupakan bagian penting dalam proses berpikir. Kajian ini bertujuan untuk menganalisis penggunaan visual mediator ketika mahasiswa melakukan penalaran statistis. Jenis penelitian ini adalah penelitian kualitatif. Mahasiswa yang terlibat dalam kajian ini sebanyak 42 mahasiswa. Empat diantara 42 mahasiswa tersebut merupakan subjek dalam penelitian ini. Teknik pengumpulan data adalah hasil tes tertulis dan hasil wawancara. Satu soal diberikan kepada mahasiswa. Soal tersebut memuat pertanyaan yang menuntut mahasiswa melakukan penalaran statistis. Analisis data dilakukan dengan cara mengidentifikasi peran visual mediator yang digunakan mahasiswa ketika mereka melakukan penalaran statistis. Hasil penelitian ini menunjukkan bahwa: 1) visual mediator dapat digunakan sebagai objek awal dan juga sebagai objek final untuk mempermudah dalam menghasilkan substantiation narrative, 2) visual mediator berupa grafik merupakan objek yang dapat mempermudah dalam membuat prediksi data time series, 3) diperlukan penggabungan berbagai visual mediator untuk memberikan substantiation narrative yang tepat dalam membuat kesimpulan dan prediksi data,  4) visual mediator yang sama pada individu berbeda dapat menghasilkan substantiation narrative berbeda dalam membuat kesimpulan dan memprediksi data.  Kajian ini memberikan implikasi bahwa penggunaan berbagai visual mediator merupakan aspek penting dalam memahami objek serta berperan menghasilkan substantiation narrative ketika melakukan penalaran statistis.   Abstract Visual mediators can be used as thinking aids in mathematical discourse and an important part of the thinking process. This study aims to analyze the use of visual mediators when students perform statistical reasoning. This type of research was qualitative research. There were 42 students involved in this study. Four of the 42 students were subjects in this study. Data collection techniques are the results of written tests and interviews. One question given to students. The question contains questions that require students to do statistical reasoning. Data analysis was carried out by identifying the visual role of the mediator used by students when they did statistical reasoning. The results of this study indicate that: 1) visual mediators could be used as initial objects and also as final objects to make it easier to produce substantiation narratives, 2) visual mediators in the form of graphs are objects that can make it easier to predict time series data, 3) it is necessary to combine various visual mediators to provide the right substantiation narrative in making conclusions and predict data, 4) the same visual mediator by different individuals can produce different substantiation narratives in making conclusions and predicting data. This study implies that using various visual mediators is an important aspect of understanding objects and plays a role in producing them