English version of the Computer Vision Symptom Scale (CVSS17)

Research hypothesis: The English and the Spanish version of the Computer Vision Symptom Scale (CVSS17) are equivalente and show similar psychometric properties.

The dataset is composed by two text files used as control file for WINSTEPS analysis:

1. Datos para DIF CVSS17 vs CVSS17ENG.txt: The first group of lines, from &INST to &END configures the analysis performed in WINSTEPS to perform a Differential Item Analysis (DIF), based on the Rasch analysis results, between CVSS17 English Version and the original version, developed in European Spanish. The line starting with "PDELETE" shows the respondents excluded from the analysis. The next 17 lines indicates the ID for each questionnaire item. The following lines, until the end of the archive, contains the responses obtained from the participant. Each line displays the responses of each person. The first letter indicates whether the respondent answered the English version (i) or the Spanish version (E) , followed by four numbers (assigned by random), followed by one digit showing whether the respondent was a male (2) or a female (1), followed by a group of two letters describing if the respondent was presbyope (>39 years old) or non presbyope. The next 17 numbers displays the option chosen by the respondent for each item (in the order defined by the labels displayed at the begining of this file), N was used to label missing responses.
2. Datos para análisis de Rasch de la CVSS17ENG.txt: The first group of lines, from &INST to &END configures the analysis performed in WINSTEPS to assess the structural validity of the CVSS17 English Version. The line starting with "PDELETE" shows the respondents excluded from the analysis. The next 17 lines indicates the ID for each questionnaire item. The following lines, until the end of the archive, contains the responses obtained from the participant. Each line displays the responses of each person. The first letter indicates thar the respondent answered the English Vesion (i), followed by four numbers (assigned by random), followed by one digit showing whether the respondent was a male (2) or a female (1), followed by a group of two letters describing if the respondent was presbyope (>39 years old) or non presbyope. The next 17 numbers displays the option chosen by the respondent for each item (in the order defined by the labels displayed at the begining of this file), N was used to label missing responses.

Those interested in using this data just need to use any of these two files as a control file for WINSTEPS analysis. The interpretation of the results will be shown in a scientific paper.

研究假设：计算机视觉症状量表（Computer Vision Symptom Scale, CVSS17）的英语版本与西班牙语版本具有等效性，且二者具备相似的心理测量学特性。

本数据集包含两份用作WINSTEPS分析对照文件的文本文件：
1. "Datos para DIF CVSS17 vs CVSS17ENG.txt"：该文件的第一组行（从&INST至&END）用于配置WINSTEPS分析流程，以基于拉施（Rasch）分析结果，针对欧洲西班牙语版原始CVSS17与英语版CVSS17开展项目功能差异（Differential Item Functioning, DIF）分析。以“PDELETE”开头的行标示了本次分析中被排除的受访者。后续17行内容分别对应各问卷条目ID。直至文件末尾的其余行则包含参与者的作答数据：每一行代表一名受访者的作答结果，首字母用以区分受访者作答的版本（i代表英语版本，E代表西班牙语版本），随后为四个随机分配的数字，接着是一位数字（1代表女性，2代表男性），其后跟随两个字母组合，用于标示受访者为老视（>39岁）或非老视群体。接下来的17个数字依次对应各条目（按照文件开头标注的条目顺序）的作答选项，其中使用N标记缺失作答。
2. "Datos para análisis de Rasch de la CVSS17ENG.txt"：该文件的第一组行（从&INST至&END）用于配置WINSTEPS分析流程，以评估英语版CVSS17的结构效度。以“PDELETE”开头的行标示了本次分析中被排除的受访者。后续17行内容分别对应各问卷条目ID。直至文件末尾的其余行则包含参与者的作答数据：每一行代表一名受访者的作答结果，首字母用以表明受访者作答的版本为英语版本（i），随后为四个随机分配的数字，接着是一位数字（1代表女性，2代表男性），其后跟随两个字母组合，用于标示受访者为老视（>39岁）或非老视群体。接下来的17个数字依次对应各条目（按照文件开头标注的条目顺序）的作答选项，其中使用N标记缺失作答。

任何希望使用本数据集的研究人员仅需将上述两份文件中的任意一份用作WINSTEPS分析的对照文件即可。相关结果的解读将在一篇学术论文中呈现。