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: Beberapa uji keterandalan kuesioner
Abstrak: Penelitian ini bertujuan untuk menganalisis keterandalan beberapa topik pada kuesioner dengan menggunakan lima metode, yaitu metode Cronbach Alpha, Spearman-Brown, Guttman, Rulon dan Analisis Ragam. Di samping itu dalam penelitian ini juga dianalisis kehomogenan dan konsistensi internal antar butir pertanyaan dari topik-topiknya. Data yang digunakan dalam penelitian ini diperoleh mahasiswa Tingkat Persiapan Bersama, Institut Pertanian Bogor, Kelompok V. dengan menggunakan kuesioner. Kuesioner yang digunakan berisi delapan belas butir pertanyaan, terdiri dari dua topik. Topik pertama berisi pertanyaan-pertanyaan tentang Evaluasi Mahasiswa Terhadap Dosen Matematika I, sedangkan topik kedua berisi pertanyaan-pertanyaan tentang Evaluasi Mahasiswa Terhadap Asisten Matematika I. Skor yang diberikan terhadap masing-masing butir pertanyaan ditetapkan berdasarkan skala pengukuran ordinal. Penarikan contoh dilakukan secara acak sebanyak 33 orang responden. Kehomogenan antar butir pertanyaan pada kedua topik yang dianalisis cukup tinggi, karena keragaman antar butir pertanyaannya sebagian besar berada pada kategori rendah.
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Judul: Elektrodeposisi Film Tipis Semikonduktor Cu2ZnSnS4 (CZTS) pada Substrat Kaca ITO
Abstrak: Semiconductor Cu2ZnSnS4 (CZTS) thin film that can be used as absorber layers on solar cell module was made via electrodeposition method. CZTS thin film was electrodeposited on the surface of a silicate glass coated with a thin layer of indium tin oxide (ITO). Deposition process was done using potentiostatic mode at room temperature with a potential of 1.05 V for 30, 45, and 60 minutes, followed with annealing the film at 2 different temperatures, 500 ºC using furnace and 180 ºC using hot plate, both treatments for 45 minutes in N2/H2S atmosphere. The X-ray difractograms were analyzed using Match 2 program and showed that the CZTS thin films had kesterit crystalline structure, with a low percentage of CZTS phase. The thin film also contained secondary phases such as Cu2S, ZnS, and SnS. The obtained CZTS thin films had a thickness between 1.039 and 1.676 μm. Absorption study showed that the band gap energy of CZTS thin films which was annealed using furnace ranged from 1.50 to 1.52 eV, whereas that annealed using the hot plate was not observed. The band gap energy value showed that CZTS thin films can be used as sunlight absorber layers on solar cell. The formation of CZTS crystal film on this investigation was effectively performed using furnace annealing process at a temperature of 500 ºC with deposition time of 45 minutes.
Keyword: Thin film, Electrodeposition, Cu2ZnSnS4