Judul: Perbandingan Skala Kontinu dan Skala Diskret
Abstrak: In social studies, researchers often measure the characteristics of coutinuously measured objects by using discrete scales. So far the discrete scale are considered among the most popular methods used in the study because it is easy and simple. For this purpose, we need scale which can put respondents answers into a particular option, but has a relatively small bias. This study focused on the measurement of the magnitude of the bias arising from the multiple scale number associated with the number of samples, the distribution of the data and the correlation between variables. We than simulated using a continuous scale and then transformed into a discrete scale with six categories, namely scale 2 - 7. For each category, the magnitude of the sample size did not significantly affect the bias. The magnitude of the bias due to the categorization of the scale in this study indicates that the more categories used the smaller the bias. Category scale that has the smallest of bias was 7 with the average value of the bias 3.32%.
Keyword: bias., correlation, categories, Scale

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: The Activity of Microalgae Extract to RNA Helicase Inhibitor Japanese Encephalitis Virus
Abstrak: Japanese encephalitis virus is an agent of encephalitis disease. Cellular target therapy is one of the ways to prevent japanese encephalitis virus which has been recently developed. Microalgae extract assesment is potential to inhibit japanese encephalitis virus through inhibition of NS3 helicase. Microalgae were taken from Batam, Pari, and Ciater. Each microalgae has been extracted by four solvents (methanol 80%, acetone 80%, hexane 80%, and etyl acetate 80%) to produce 101 extracts. The ATPase assay was used on inhibition activity of the extracts, whereas for the toxicity method done is Brine Shrimp Lethality Test. The results showed that five microalgae extracts have a high inhibition activity which are CTR 07-09 etyl acetate 80% (97,19331%), CTR 07-10 etyl acetate 80% (95,61652%), CTR 07-01 etyl acetate 80% (95,1661%), CTR 06-08 etyl acetate 80% (94,54431%), and CTR 07-07 etyl acetate 80% (94,22955%). Then the five of microalgae extracts were tested with the toxicity test to calculate LC50 value. Microalgae extract of CTR 06-08, CTR 07-09, and CTR 07-10 have a character of non-toxic, whereas microalgae extract of CTR 07-01 and CTR 07-07 have a character of toxic.
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