Aydin Orhan, Yassikaya Muhammed Yasin
Research Institute for Individuals with Disabilities, Anadolu University, 6470 Eskişehir, Turkey.
Department of Special Education, Recep Tayyip Erdogan University, 53100 Rize, Turkey.
Perspect Behav Sci. 2021 Mar 31;45(1):239-257. doi: 10.1007/s40614-021-00284-0. eCollection 2022 Mar.
Access to raw data of graphs presented in original articles to calculate the effect size of single-case research is a challenge for researchers conducting studies such as meta-analysis. Researchers typically use data extraction software programs to extract raw data from the graphs in articles. In this study, we aimed to analyze the validity and reliability of the PlotDigitizer software program, which is widely used in literature and an alternative to other data extraction programs, on computers with different operating systems. We performed the digitization of 6.846 data points on three different computers using 15 hypothetical graphs with 20 data series and 186 graphs with 242 data series from 29 published articles to accomplish the goal. Besides, using the values we digitized, we recalculated the 23 effect sizes presented in the original articles for validity analysis. Based on our sampling, we calculated intercoder and intracoder Pearson correlation coefficients. The results showed that PlotDigitizer could be an alternative to other programs as it is free and can run on many current and outdated systems, and it is valid and reliable as it is nearly perfect. Based on the obtained results and considering the data extraction process, we presented various recommendations for the researchers that will use the PlotDigitizer program for the quantitative analysis of single-case graphs.
对于进行荟萃分析等研究的人员而言，获取原始文章中呈现的图表的原始数据以计算单病例研究的效应量是一项挑战。研究人员通常使用数据提取软件程序从文章中的图表中提取原始数据。在本研究中，我们旨在分析PlotDigitizer软件程序在不同操作系统的计算机上的有效性和可靠性，该软件在文献中被广泛使用，是其他数据提取程序的替代品。为实现这一目标，我们使用来自29篇已发表文章的15个包含20个数据系列的假设图表和186个包含242个数据系列的图表，在三台不同的计算机上对6846个数据点进行了数字化处理。此外，我们利用数字化后的值，重新计算了原始文章中呈现的23个效应量以进行有效性分析。基于我们的抽样，我们计算了编码员间和编码员内的皮尔逊相关系数。结果表明，PlotDigitizer可以作为其他程序的替代品，因为它是免费的，并且可以在许多当前和过时的系统上运行，而且由于其近乎完美，所以它是有效且可靠的。基于获得的结果并考虑到数据提取过程，我们为将使用PlotDigitizer程序对单病例图表进行定量分析的研究人员提出了各种建议。
