PhD-delay Dataset for Online Stats Training

This is a dataset used for the online stats training website (https://www.rensvandeschoot.com/tutorials/) and is based on the data used by Van de Schoot, Yerkes, Mouw and Sonneveld 2013 Among many other questions, the researchers asked the Ph.D. recipients how long it took them to finish their Ph.D. thesis (n=333). It appeared that Ph.D. recipients took an average of 59.8 months (five years and four months) to complete their Ph.D. trajectory. The variable B3_difference_extra measures the difference between planned and actual project time in months (mean=9.97, minimum=-31, maximum=91, sd=14.43). For the the exercises we are interested in the question whether age (M = 31.7, SD = 6.86) of the Ph.D. recipients is related to a delay in their project. The relation between completion time and age is expected to be non-linear. This might be due to that at a certain point in your life (i.e., mid thirties), family life takes up more of your time than when you are in your twenties or when you are older. So, in our model the gapgap (<em>B3_difference_extra</em>) is the dependent variable and ageage (<em>E22_Age</em>) and age2age2(<em>E22_Age_Squared </em>) are the predictors. For more information on the sample, instruments, methodology and research context we refer the interested reader to Van de Schoot, Yerkes, Mouw and Sonneveld 2013.本数据集专为在线统计培训网站（https://www.rensvandeschoot.com/tutorials/）开发，其数据源自Van de Schoot、Yerkes、Mouw与Sonneveld 2013年的研究。在诸多调研问题中，研究者向333名博士毕业生（n=333）询问了完成博士学位论文所需的时长，结果显示受访者平均耗时59.8个月（即5年4个月）完成博士学业。变量B3_difference_extra用于衡量计划项目时长与实际项目时长的差值（单位：月），其均值为9.97、最小值为-31、最大值为91、标准差为14.43。针对本次练习，我们关注的核心问题为：博士毕业生的年龄（均值M=31.7，标准差SD=6.86）与其项目延期是否存在关联，且预期完成时长与年龄呈非线性关系。该非线性关联可能源于：人生特定阶段（如三十五岁左右），家庭生活占用的时间会多于二十余岁或更年长的时期。因此，本模型中，因变量为gapgap（即B3_difference_extra），预测变量为ageage（即E22_Age）与age2age2（即E22_Age_Squared）。如需了解样本、调研工具、研究方法与研究背景的更多细节，敬请参考Van de Schoot、Yerkes、Mouw与Sonneveld 2013年的研究成果。