Creating web applications for online psychological experiments: A hands-on technical guide including a template.

The present tutorial provides a technical overview of how to create web applications for online psychological experiments from scratch via the HTML/CSS/JavaScript framework. This approach allows virtually unlimited flexibility in accomplishing anything in an online experiment that a regular computer (or smartphone, etc.) is capable of. Apart from offering a fast introduction for complete beginners, this tutorial may also serve as a helpful guideline for more experienced programmers and researchers. Connected to the tutorial, a specific implementation is also given via the free and open-source template project at https://github.com/gasparl/expapp , intended to be improved by the community to always follow the latest technological advancements and general good practices.

Testing Sleep Consolidation in Skill Learning: A Field Study Using an Online Game.

Using an observational sample of players of a simple online game (n > 1.2 million), we are able to trace the development of skill in that game. Information on playing time, and player location, allows us to estimate time of day during which practice took place. We compare those whose breaks in practice probably contained a night's sleep and those whose breaks in practice probably did not contain a night's sleep. Our analysis confirms experimental evidence showing a benefit of spacing for skill learning, but it fails to find any additional benefit of sleeping during a break from practice. We discuss reasons why the well-established phenomenon of sleep consolidation might not manifest in an observational study of skill development. We put the spacing effect into the context of the other known influences on skill learning: improvement with practice, and individual differences in initial performance. Analysis of performance data from games allows experimental results to be demonstrated outside of the lab and for experimental phenomenon to be put in the context of the performance of the whole task.

QRTEngine: An easy solution for running online reaction time experiments using Qualtrics.

Performing online behavioral research is gaining increased popularity among researchers in psychological and cognitive science. However, the currently available methods for conducting online reaction time experiments are often complicated and typically require advanced technical skills. In this article, we introduce the Qualtrics Reaction Time Engine (QRTEngine), an open-source JavaScript engine that can be embedded in the online survey development environment Qualtrics. The QRTEngine can be used to easily develop browser-based online reaction time experiments with accurate timing within current browser capabilities, and it requires only minimal programming skills. After introducing the QRTEngine, we briefly discuss how to create and distribute a Stroop task. Next, we describe a study in which we investigated the timing accuracy of the engine under different processor loads using external chronometry. Finally, we show that the QRTEngine can be used to reproduce classic behavioral effects in three reaction time paradigms: a Stroop task, an attentional blink task, and a masked-priming task. These findings demonstrate that QRTEngine can be used as a tool for conducting online behavioral research even when this requires accurate stimulus presentation times.