### Longitudinal Preregistation ### **Scope and Background** Preregistration is the process of specifying project details, such as hypotheses, data collection procedures, and analytical decisions, prior to conducting a study. It is designed to make a clearer distinction between data-driven, exploratory work and a-priori, confirmatory work. Both modes of research are valuable, but are easy to unintentionally conflate. See the [Preregistration Revolution][1] for more background and recommendations. For longitudinal research, there is an increased risk of analysts being biased by preliminary trends in the first rounds of data collection. In addition, prespecifying analyses that are likely to occur many months or years in the future can be daunting. However, those challenges can be balanced by proper blinding to any summary statistics in the dataset and the use of hold out datasets (where the "training" and "validation" datasets are kept separate from each other). See [this page][2] for specific recommendations about "split samples" or "hold out" datasets. Finally, if those procedures are not followed, disclosure of possible biases can inform the researcher and their audience about the proper role any results should have (i.e. the results should be deemed mostly exploratory and ideal for additional confirmation). This project contains a template for creating your preregistration. In the future, this template will be integrated into the OSF. **Instructions for how to use this project** - [Fork][3] this project to make your own copy. - Complete the template by one of these three options: - Download the included word doc in project files and [upload][4] the completed form. - Make a copy of the Google doc and [attach][6] it to this project. - [Edit the wiki][7] titled "Preregistration Template" - [Register][8] this project using the "[OSF Standard Pre-data Collection][9]" form. - We recommend deleting these instructions from your wiki before registering your project. You can put some background material or the abstract in this space instead. - If you have any questions, please see our [support][10] resources. [1]: http://www.pnas.org/content/early/2018/03/08/1708274114 [2]: https://osf.io/kgnva/wiki/Open%20Science%20Literature/ [3]: https://help.osf.io/hc/en-us/articles/360019737914-Fork-a-Project [4]: https://help.osf.io/hc/en-us/articles/360019930613-Upload-files [5]: https://docs.google.com/document/d/1U1EklmhtU-f-am8q9je3eaHz00PEK47eb-Cbqe7eaFU/edit# [6]: https://help.osf.io/hc/en-us/articles/360019737374-Connect-Google-Drive-to-a-Project [7]: https://help.osf.io/hc/en-us/articles/360019737474-Edit-the-Wiki [8]: https://help.osf.io/hc/en-us/articles/360019930893-Register-Your-Project [9]: https://help.osf.io/hc/en-us/articles/360019738794-Understand-Registration-Forms [10]: https://osf.io/support/