This page contains all the collected study materials and instructions from authors that we have compiled. We also include any comments from other contributors or follow up instructions that we have learned since the beginning of the project. Click "read more" below or choose the "Wiki" option above for further information. For technical problems, please contact OSF help desk (support@osf.io) For questions or information about the studies contact either either Jon Grahe (graheje@plu.edu) or Mark Brandt (m.j.brandt@tilburguniversity.edu) so that the materials can be made available on this website. **Abstract** Mind wandering is a phenomenon in which attention drifts away from the primary task to task-unrelated thoughts. Previous studies have used self-report methods to measure the frequency of mind wandering and its effects on task performance. Many of these studies have investigated mind wandering in simple perceptual and memory tasks, such as recognition memory, sustained attention, and choice reaction time tasks. Manipulations of task difficulty have revealed that mind wandering occurs more frequently in easy than in difficult conditions, but that it has a greater negative impact on performance in the difficult conditions. The goal of this study was to examine the relation between mind wandering and task difficulty in a high-level cognitive task, namely reading comprehension of standardized texts. We hypothesized that reading comprehension may yield a different relation between mind wandering and task difficulty than has been observed previously. Participants read easy or difficult versions of eight passages and then answered comprehension questions after reading each of the passages. Mind wandering was reported using the probe-caught method from several previous studies. In contrast to the previous results, but consistent with our hypothesis, mind wandering occurred more frequently when participants read difficult rather than easy texts. However, mind wandering had a more negative influence on comprehension for the difficult texts, which is consistent with the previous data. The results are interpreted from the perspectives of the executive-resources and control-failure theories of mind wandering, as well as with regard to situation models of text comprehension. **Materials** We had previously posted two files shared by the authors called "MW experiment 1 easy passages.txt" and "MW experiment 1 hard passages.txt", however these files represented earlier drafts of the materials and there are slight differences from what they actually used in the study. We have updated our materials with the correct passages in these files: [Easy Passages.docx][1] and [Difficult Passages.docx][2]. Likewise, a previous version of the file including the comprehension questions did not include a key for the correct responses. [The most recent version][3] of this file includes the answer key. The original study was conducted in a program called DirectRT. The original materials were somewhat incompatible with current versions of DirectRT and the software is not inexpensive, so Brady Wiggins has created a version of the study using the free open source software, OpenSesame. OpenSesame can be downloaded at [http://osdoc.cogsci.nl/][4]. The OpenSesame version of this replication can be found here: [FengReplication.osexp][5]. We highly recommend that if you are unfamiliar with OpenSesame you run one or more of the tutorials in order to understand how this experiment is programmed and how your data output will appear. If you believe you have found any errors in the FengReplication.osexp file, please contact Brady Wiggins (wigginsb@byui.edu) CREP teams are welcome to adapt the study to other software platforms. The study would ideally operate in full-screen mode and should require participants to advance using keystrokes (e.g., [space], "y", "n", etc.) without any option to return to previous screens. The software must be able to accurately and precisely record the time from the presentation of the stimulus to a keystroke from the participant. Finally, Feng, D'Mello, and Graesser have shared their original data and the R code from their analysis. These files can guide CREP teams programming the study on their own to ensure that they are collecting all necessary variables. Likewise, they can serve as a model for how to compile and analyze data for this study. [1]: https://osf.io/42gnf/ [2]: https://osf.io/dwn5m/ [3]: https://osf.io/rvppv/ [4]: http://osdoc.cogsci.nl/ [5]: https://osf.io/9qrk8/