Implementation Details ---------------------- This page describes how our lab implemented the procedures required by the official protocol for the RRR. It also describes and justifies any additions to or departures from that protocol. You can view the official protocl and the main project page for this RRR using these links: - Official Protocol: [https://osf.io/ypd78/][1] - Main RRR project page: [https://osf.io/scu2f/][2] ---------- #### Experimenters #### Julie Novakova is a researcher at the Department of Philosophy and History of Science at the Faculty of Science, Charles University in Prague. She has a background in evolutionary biology and psychology. In her diploma thesis, she studied cooperation, altruism and fairness preferences in connection to one's health, using experimental games methodology. Petr Houdek is an assistant professor at the Jan Evangelista Purkyně University and the University of Economics in Prague. He works in the field of behavioral economics and psychology and has extensive experience with replication studies (e.g. ManyLabs). Jaroslav Flegr is a professor at the Department of Philosophy and History of Science at the Faculty of Science, Charles University in Prague. He has a background in evolutionary biology and psychology. ---------- #### Setting/Lab/Equipment #### We will use the CEBEX (Center for Behavioral Experiments in Prague) lab for conducting the study. It contains 17 computer stations divided by partitions, so that no participants are able to see others' screens. The computers in the CEBEX lab are running Windows 7 and are fully capable of enabling access to a Qualtrics survey during their web browser interface. ![Picture of the lab][3] ---------- #### Sample, subjects, and randomization #### **Target sample size:** We will use a sample of approximately 200 students, 100 for each setting. **Target sample demographics:** We will use undergraduate students of the Charles University as our sample. Therefore, based on the demographics of the whole group, we expect the mean and median age to be around 21 and the gender ratio to be around 55 percent male, 45 percent female. **Minimum sample size after exclusions:** Our minimum sample size is 80 participants in each condition (after exclusion). **Stopping rule(s):** The recruitment of our subjects will commence at the beginning of the first semester (October 2015). Based on previous experiments, we expect a sufficient number of undergraduate students to apply. We will invite 17 students (the number of computer stations in the lab) for each session: 16 as participants in the study, 1 as a substitute in case another participant did not arrive (if all arrive, the substitute will get a small show-up reward). The collection of data will stop when we reach or exceed our target sample size of cca 200 (therefore after at least 12 sessions). If the size of the sample after exclusion decreased under 80 participants in either condition and we needed additional participants later, we would make another recruitment call (through flyers in the university halls and social media calls) and run further sessions until we have a minimum of 80 participants in both conditions. **Randomization to conditions:** Participants will be randomly assigned to conditions by the provided Qualtrics Script. **Blinding to conditions:** The participants will be invited to participate in a decision-making study. They will all receive the same general instructions with no mention of two different settings. From the beginning of the Qualtrics survey, they will follow the instructions on their screens and won't be able to see each other's screens or behavior (the computer stations are divided by partitions) and deduce that someone else may have different instructions. **Exclusion rules:** We will be using exclusion rules stated in the official protocol. The collected data will be examined regularly by one of the junior researchers in our lab, who will remain blind to the time pressure condition assignment. **Procedures for handling testing sessions for which the number of participants is not a multiple of 4:** We plan to invite 17 subjects for each session, one of them as a substitute. If all arrive, the substitute gets a small show-up reward and does not participate in the experiment. If one participant does not arrive, the substitute takes her/his place. If more than one fail to show up, those not able to participate in this study would be assigned other experimental tasks. We are currently considering the possibilities for which tasks to include and whether to use them also for the planned substitutes. ---------- #### Software/Code #### We confirm that we will be using the provided materials, including the Qualtrics scripts, and that they work in our laboratory. ---------- #### Differences from the official protocol #### We know of nothing that would cause us to deviate from the protocol in any way. The only difference is that we will be using materials translated into Czech. Julie Novakova, the administrator of this project (also working as a professional translator), will translate them and subsequently a bilingual speaker will back-translate them to ensure their accuracy. We will upload all the files here when the translation and back-translation are ready. The amounts of money will be set based on the currency rates and utility of money in the Czech Republic vs. USA. The current rate (as of 07/17/2015) is 1 USD to 25 CZK (see [here][4]). The purchasing power in the Czech Republic is 36.23% lower than in United States (see [here][5]). Therefore the amount available for the participant for the Public Goods Game would be 63.77 (4 USD = 100 CZK, minus 36.23% gives 63.77), which we round to 65 CZK. [1]: https://osf.io/ypd78/ [2]: https://osf.io/scu2f/ [3]: http://s27.postimg.org/z4gdph91f/IMAG0956.jpg [4]: http://themoneyconverter.com/USD/CZK.aspx [5]: http://www.numbeo.com/cost-of-living/compare_countries_result.jsp?country1=United%20States&country2=Czech%20Republic