Gradepen vs PhotoMetrix

Grade automatically the answer keys of shuffled tests with Gradepen! Gradepen.com allows you to create short tests and exams including open-ended and objective questions or reusing questions shared by other users. The exams may have the order of questions and items automatically shuffled to hinder the occurrence of fraud. The objective questions are graded automatically with this App using your device's rear camera. The teacher may also inform the grades of open-ended questions to be totaled in the final test score. You can export the results to a spreadsheet and forward it by email. Promotionally, the grading of assessments with up to five questions of a maximum of five items is free. Don't miss our promotional packages and grade your assessments in seconds with Gradepen! Check our website: www.gradepen.com

This app employs Single Linear Correlation technics for univariate analysis and Principal Component Analysis (PCA) for multivariate exploratory analysis, including Partial Least Square Regression (PLS). The image data are acquired using the device main camera and photo album, both converted in RGB histograms. In addition, apart color channels of RGB, HSV, HSL and HSI systems are used during the univariate and multivariate processes. It is possible to send by e-mail the image data, analysis data and charts. In order to validate the obtained results, the same sets of data were tested using Microsoft Excel© and ChemoStat©. The results in both applications coincided in various combinations. This app calculates and plot: eigenvalues, eigenvectors, scores, loadings using Singular Value Decomposition in Multivariate Analysis. This app calculates and plot: slope (span), intercept (off-set) and regression (Pearson product-moment correlation coefficient) in Univariate Calibration Analysis. http://dx.doi.org/10.5935/0103-5053.20160182