Judul: Sensitivitas Skala Data terhadap Pengujian Nilai Tengah
Abstrak: In many surveys, researchers have often to deal with qualitative or categorical measurements. Sometimes, even continuous objects or characteristics have to be measured by using a discrete scale. It may be caused by the inability of researchers to perform measurements or scoring of an object precisely using continuous scale. This will reduce the degree of accuracy of the actual conditions of the measurement results. Therefore, it can imply bias in the results of statistical tests performed. This research is intended to measure the bias of T-test on categorical data based on various sample sizes and data distributions. Moreover, this research aims to determine the optimal combination between the number of categories and the number of sample size to produce a certain bias. This study focuses on the statistical test to compare the characteristics between two groups or populations. The bias is measured as a margin of error of the confidence interval. Preliminary data are generated by a computer program and then they are split into two to fifteen categories on the same interval. The results of the study are as follows. For normally and Poisson distributed data, increasing number of categories or sample size will imply decreasing average margin of error. An explicit bias function according to sample size and category has been proposed. Categorization of data can increase the bias in the confidence interval, but fortunately the bias doesn’t change the conclusion of the -test.
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Judul: Perbandingan Uji Reliabilitas Cronbach Alpha untuk Data Berskala Rasio dan Ordinal
Abstrak: A reliability test is often performed on survey data. The goal is to determine the data characteristics both in terms of consistency and accuracy. The reliability test has a condition that to be satisfied, i.e., the data must be continuous (ratio), while the data obtained from a survey is commonly an ordinal type. This paper aims to measure the magnitude of the bias related to reliability test and the patterns of alleged bias related to the number of categories and the number of data samples surveyed. It was shown in this work, as the number of categorized ordinal data and the number of sample data increase, the amount of bias decreases. It was also shown that by assigning 6 categories ordinal data scales and the number of data sample was 400, the level of bias would be not more than 5%.
Keyword: Bogor Agricultural University (IPB), reliability test., ratio scale, ordinal scale

Judul: Sintesis 1-Kloro-2-metoksi-6-propilnaftalena-1,3-dioksolana (1:1) sebagai Prekursor Asam (S)-(+)-(6-Metoksi-2-naftil)propanoat
Abstrak: Senyawa 1-kloro-2-metoksi-6-propilnaftalena-1,3-dioksolana (1:1) sebagai prekursor asam (S)-(+)-(6-metoksi-2-naftil)propanoat disintesis dari bahan awal 2-metoksinaftalena. Tahapan sintesis diawali dengan klorinasi menggunakan 2 jenis pereaksi klorinasi, yakni isosianurat terklorinasi dan NaOCl. Klorinasi dengan isosianurat terklorinasi berhasil menyintesis 1-kloro-2-metoksinaftalena sebagai produk monoklorinasi melalui pencirian dengan kromatograf gas-spektrometer massa (GC-MS). Nisbah konversi produk paling efisien diperoleh pada laju penambahan 2.5 mmol/jam. Sebaliknya, klorinasi dengan NaOCl menghasilkan produk triklorinasi. 1-Kloro-2-metoksinaftalena selanjutnya diasilasi dengan propanoil klorida, tetapi analisis dengan GC menunjukkan bahwa produk asilasi tidak terbentuk. Sistem bebas-air diperlukan untuk keberhasilan proses asilasi tersebut.
Keyword: isosianurat terklorinasi, NaOCl, nisbah konversi