Interpretation Of Correlation Coefficient Research Articles

Experimental study of binderless briquetting process: effect of temperature on the fuel briquettes from rice husks

In developing countries’ socio-environmental background, fossil fuel use is evolving at the same time as deforestation, resulting in desertification and global warming. There is an urgent need to find alternative sustainable and environmentally friendly sources such as biomass briquettes. This study aims to analyse the effect of densification temperature on characteristics of biomass briquettes produced from rice husks. The densification temperatures applied to each production run varied from 0 to 350°C with an increment of 50°C in a heating screw press. Physical and proximal analysis of briquettes produced at each stage of temperature is done in order to determine bulk density, moisture content, Ash content, volatile matter according to NF standard. A statistical analysis was applied in order model the relationship between briquettes’ characteristics and densification temperature. Interpretation of correlation coefficients (0,98) shows that there is a strong correlation between densification temperature and briquette density. As temperature increases, density also increases. However, the correlation (r = 0,44) between densification temperature and ash content is very low, and there is no significant impact.

Pengaruh Ekstrakurikuler dan Motivasi Belajar terhadap Hasil Pembelajaran Mahasiswa STIE AAS Surakarta

The research aims to analyze the influence of English Fun Club extracurricular and learning motivation on the learning outcomes of Bahasa Inggris 2 subject of STIE AAS Surakarta students. It is assumed that the significant different in the students daily scores and semester scores is influenced by these two variables. This research is a quantitative approach using population study or census. The population of this research is the fourth semester students of STIE AAS Surakarta who take part in the English Fun Club activities, totaling 67 people in the odd semester of the 2020/2021 academic year and all of them are taken as research subjects. The data collection techniques using documentation and questionnaires. The instrument validity is tested using Product Moment and the reliability is tested using Cronbach Alpha. The data is analyzed using multiple linear regress analysis. Based on the interpretation of correlation coefficient and tested using product moment correlation formula, the results is 0.693 which proves that extracurricular activities have positive influence on learning outcomes. While the results of the partial calculation of the influence of learning motivation on the learning outcomes with regression coefficient value (b) 0.663, at a significance level of 5%, the tcount is 9.984 with a significance value of 0.000. The regression coefficient has positive value and a significance value (p) <0.05, it can be concluded that there is positive influence of learning motivation on English learning outcomes for STIE AAS Surakarta students.

The Students’ Frequency of Wacthing YouTube with Learning Contents and Their Speaking Skill at 4th Semester of English Department of IAIN

The aim of this study is to find out whether there is a correlation between students’ frequency of using YouTube content and speaking skill at 4th semester of English Department of IAIN Bengkulu. This study was conducted in correlational research which involved 21 students. A questionnaire was used to obtain students’ frequency of using YouTube content and test was employed to obtain students’ speaking skill. Both data were calculated using Pearson Product Moment Formula and SPSS Program. The result of this study showed that the coefficient correlation (rcount) was higher than the rtable (0,852 > 0,433). It can be said that there is a significant correlation between students’ frequency of using YouTube content and their speaking skill at 4th semester of English Department of IAIN Bengkulu. The interpretation of correlation coefficient 0,852 was high correlation. The hypothesis accepted in this research was alternative hypothesis (Ha), whereas the null hypothesis (Ho) was rejected. In brief, it could be drawn that students’ frequency of using YouTube was correlated with their speaking skill.

Correlation Coefficients: Appropriate Use and Interpretation.

Correlation in the broadest sense is a measure of an association between variables. In correlated data, the change in the magnitude of 1 variable is associated with a change in the magnitude of another variable, either in the same (positive correlation) or in the opposite (negative correlation) direction. Most often, the term correlation is used in the context of a linear relationship between 2 continuous variables and expressed as Pearson product-moment correlation. The Pearson correlation coefficient is typically used for jointly normally distributed data (data that follow a bivariate normal distribution). For nonnormally distributed continuous data, for ordinal data, or for data with relevant outliers, a Spearman rank correlation can be used as a measure of a monotonic association. Both correlation coefficients are scaled such that they range from -1 to +1, where 0 indicates that there is no linear or monotonic association, and the relationship gets stronger and ultimately approaches a straight line (Pearson correlation) or a constantly increasing or decreasing curve (Spearman correlation) as the coefficient approaches an absolute value of 1. Hypothesis tests and confidence intervals can be used to address the statistical significance of the results and to estimate the strength of the relationship in the population from which the data were sampled. The aim of this tutorial is to guide researchers and clinicians in the appropriate use and interpretation of correlation coefficients.

Assessing students’ abilities in interpreting the correlation and regression analysis

A case study was carried out on students who were being exposed to some theoretical concepts of the correlation and regression topics to investigate their ability to compute and interpret the Pearson’s correlation coefficient and the slope of regression. The findings revealed that a low percentage of students (19.43%) successfully completed their interpretation of correlation coefficient and 33.18% of the students managed to interpret the computed value of regression slope completely. It was also found that the students’ ability to interpret regression slope was significantly associated with the ability to interpret the correlation coefficient correctly. It is hoped that the findings obtained from this study will shed some light on improving teaching practices of statistics educators so as to help students in gaining better understanding on interpreting the correlation and regression analysis. Keywords: correlation; Pearson; regression; coefficients; interpretation; students’ ability

A DETAIL ANALYSIS OF ELECTRICAL AND OPTICAL FLUCTUATIONS OF GREEN LIGHT-EMITTING DIODES BY CORRELATION METHOD

A detail analysis of electrical and optical fluctuations of large power (1 W) green light-emitting diodes (LEDs) is presented. Special attention was directed to measurement and interpretation of correlation coefficient between electrical and optical fluctuations. The correlation coefficient was measured not only over frequency range from 10 Hz to 20 kHz, but also in every one-octave frequency band by using digital filters. It is shown that correlated part of electrical and optical fluctuations for investigated green LEDs is related with random potential fluctuations of parameters of quantum well due to charge carrier capture by the defects in the active layer, while uncorrelated part of electrical noise is caused by parallel leakage channel which resistance is many times higher than that of p-n junction.

Income and well-being: How big is the gap between the rich and the poor?

One of the most enduring debates in the literature on subjective well-being concerns the importance of money. Studies consistently show that the correlation between income and well-being is small. This evidence has been interpreted to mean that money does not matter and that people’s intuitions about the causes of happiness are wrong. However, correlation coefficients are notoriously difficult to interpret, and thus it is possible that lay people’s intuitions are correct, whereas psychologists’ interpretation of correlation coefficients is wrong. Data from two large-scale studies replicate the relatively weak correlation between income and happiness. However, both studies show that these small correlations translate into large mean differences between rich and poor groups. These mean differences are medium in size even when the wealthy are compared to average. In addition, measurement error has negligible effects on the correlation coefficient, but has strong effects on the rich/poor happiness gap.

Analysis and interpretation of data from real-time PCR trace detection methods using quantitation of GM soya as a model system.

Recent years have seen an increased interest in DNA trace detection methods involved in many areas of bioanalytical research, such as quantitation of genetically modified (GM) ingredients in food products. There is little in the way of standardisation of data handling from these methods, and the data generated needs to be analysed appropriately if the results are to be interpreted correctly. This paper describes particular aspects of real-time PCR trace detection methods in order to increase the understanding of data generated using this bioanalytical technique. Using the specific example of GM soya detection and quantitation, it focuses on the production of calibration curves based on the mean and individual data values, the interpretation of correlation coefficients, regression techniques, and discusses suitable data analysis arising from simple and more complex experimental designs following transformation. By using the approaches outlined in this paper, more accurate analysis of data from real-time PCR and GM trace detection methods could be achieved.

Correlations, Sample Size, and Practical Significance: A Comparison of Selected Psychological and Medical Investigations

Abstract A common interpretation of correlation coefficients is that values of r that are less than .30 are considered “low.” Correlations at about this value are quite common in psychological studies, and this situation often leads to questions concerning the validity of the findings. In this article, some comparative correlational findings in medical research are presented, showing that many important medical and societal decisions have been made on the basis of similar or lower calculated correlation coefficients. The influence of sample size and issues of practical significance are also discussed.

Asymmetric measures of association, closed data, and multivariate analysis

The association between constant-sum variables Xiand Xjexpressed as percentages can be calculated as a product-moment correlation between Xiand Xj/(100 − Xi) and a correlation between Xjand Xi/(100 − Xj). An asymmetric, square matrix may be formed from these coefficients, and multivariate analysis performed by two methods: singular value decomposition and canonical decomposition. Either analysis avoids problems in the interpretation of correlation coefficients determined from closed arrays, and provides information about dependencies among the variables beyond that obtained from the usual correlation coefficient between Xiand Xj.Two examples show the canonical decomposition to have the greater usefulness.

The Effects of Normality Violations on the Interpretation of Correlation Coefficients

A Monte Carlo simulation technique is used to examine the effects of normality violations on the interpretation of Pearson product-moment correlation coefficients. The findings tentatively indicate that when conventional tests of significance are used even rather severe normality violations do not substantially distort the probability of rejecting the null hypothesis that rho equals zero when this hypothesis is true.

SOME CONSIDERATIONS IN THE USE OF HALF-LIST SPEECH DISCRIMINATION TESTS.

Twenty-five word speech discrimination tests are discussed with respect to part-whole correlations, the interpretation of correlation coefficients, and the concept of validity. The assumptions underlying the interpretation of reliability coefficients are discussed. The conclusions are that the reliability of 25-word tests has not been demonstrated and that the 50-word list is being used as a sort of criterion but is a fallible measure subject to the same kind of error as the half-list.

The interpretation of correlation coefficients in terms of departure from perfect correlation.

The interpretation of correlation coefficients in terms of departure from perfect correlation.