Aims and Scope
The Journal of Experimental Political Science (JEPS) features cutting-edge research that utilizes experimental methods or experimental reasoning based on naturally occurring data. We define experimental methods broadly: research featuring random (or quasi-random) assignment of subjects to different treatments in an effort to isolate causal relationships in the sphere of politics. JEPS embraces the different types of experiments carried out as part of political science research, including survey experiments, laboratory experiments, field experiments, lab experiments in the field, natural and neurological experiments.
Types of Article
The journal accepts the following types of articles:
- Research Article*
- Short Report*
- Replication Study*
- Preregistered Report*
- Meta-Analysis*
* All or part of the publication costs for these article types may be covered by one of the agreements Cambridge University Press has made to support open access. For authors not covered by an agreement, and without APC funding, please see this journal's open access options for instructions on how to request an APC waiver. No open access publishing fees will be charged for Editorials, Introductions and Correction Notices.
Research Articles (4000 words) report novel empirical and/or theoretical findings based on well-designed and executed original experiments.
Short Reports (1000 words) are concise summaries of findings that do not meet the level of theoretical and/or empirical contribution showcased in research articles, but do inform best practices, measurement, or show innovations in experimental designs and protocols that would be of broad interest to experimentalists.
Replications (3000 words) are concise summaries of replications of previous experimental findings. Authors should make the case that the replications are informative (e.g., well-powered with consideration given to any key factors — such as context, sample, mode of treatment, etc. — that vary between the original and the replication).
Meta-Analyses (3000 words) are concise summaries of an analyses of previously reported experimental findings (both published and unpublished) that inform a well-defined question or domain in the study of politics.
Registered Reports: JEPS welcomes registered reports of any of the above article types for results-blind review. See here for more details on this submission format.
Studies accepted for fielding by Time-sharing Experiments for the Social Sciences can now be considered for preacceptance as a Registered Report. See here for more details.
Preparing your article for submission
All manuscripts should contain the following in the main text:
- Word count on the title page.
- Make explicit how the experimental design relates to the hypotheses.
- Explain how the sample size was determined and note statistical power.
- For submissions with empirical analyses, clearly describe the methods used to generate and recruit the sample. We discourage use of the term “nationally representative” and instead request that authors describe any and all efforts taken to approximate the target population.
- Clearly state any criteria used to exclude cases (e.g., item non-response) and the number of cases excluded. Authors should also clearly report any attrition and whether it occurred pre- or post-treatment. Cases should not be excluded on the basis of post-treatment variables such as manipulation checks or total survey time.
- Report all experimental conditions and disclose all post-treatment measures.
- Means of the dependent variable(s) by experimental conditions, along with standard deviations, and Ns should be reported.
- Exact p-values should be reported in the text and confidence intervals should be shown in figures. In general, authors should only describe a p-value as statistically significant if it is less than 0.05. However, if a study is pre-registered, authors may state and justify an alternative threshold for statistical significance.
- Lack of statistical significance is not sufficient evidence for “no effect.” If authors wish to make a claim that a treatment had “no effect,” they should report Bayesian Factors with well-justified priors or use an alternative method to support a claim of no substantively meaningful effect.
- Human subjects approval (if appropriate for your submission type).
- If the experiment(s) are preregistered:
- Provide a link to the anonymized preregistration document
- Report all preregistered results (even if briefly)
- Explicitly label analyses that were not preregistered
- Detail any departures from the preregistration in the main text of the manuscript and offer an explanation for the deviation
Standards for publication
JEPS is a general field journal that publishes work in all empirical subfields of political science using experimental methods to identify causal effects. To be published, the editorial team must deem a manuscript to offer 1) a strong theoretical and/or empirical contribution, 2) an appropriate, rigorous, well-powered experimental design, and 3) statistical analyses that are appropriate, clear, and transparent. We encourage authors to make explicit how their manuscript fulfills these criteria within the page limit of the article type they have selected to submit. Clever use of the Supplemental Appendix should help authors meet the page limit.
Consistent statistically significant results (i.e., “all of our hypotheses are correct”), is not a criterion for publishing in JEPS. We seek to publish research that “tells it like it is.” In this respect, authors should not feel the pressure to present unexpected findings as if they were expected. If the results are not consistent with a hypothesis, just indicate that. Although it is not required, we have observed that authors benefit from preregistering their hypotheses and designs by being able to transparently communicate what the hypotheses were at the outset of the experiment. Along these lines, preregistered designs also allow authors to label clearly which analyses are confirmatory and which analyses are exploratory. We welcome research that provides exploratory analyses of experimental data, as long as it is clearly labeled as such. The Registered Report track allows authors to build this level of transparency into the review process and ensures that reviewers and editors are not inadvertently allowing the empirical results to drive their judgments about the significance of the contribution.
While JEPS takes a broad view of what counts as an experiment, the burden rests with authors to articulate why their design identifies the causal effect that they are studying. Authors that use research designs that exploit ostensibly exogenous variation in observational settings (e.g., “natural experiments”) or a non-random manipulation of the theoretical variable of interest (e.g., within-subject designs, behavioral games, etc.) should consider alternative explanations and the sensitivity of the results to confounders. Note that experimental designs that use randomization do not automatically provide sufficient evidence for causal identification. Authors should articulate how the randomization adequately simulates the counterfactual conditions that their hypotheses imply. Moreover, designs that interact an observationally measured moderator with randomized manipulations do not offer unambiguous evidence that the moderator is causally responsible for heterogenous treatment effects. In these cases, authors should consider alternative explanations and the sensitivity of the results to confounders. Relatedly, mediation analyses do not offer unambiguous evidence for causal mechanisms, and we strongly encourage authors to provide sensitivity analyses and shy away from causal language.
JEPS welcomes informative replications. By informative, we mean that the replication makes a sufficient empirical contribution to our knowledge about a causal effect of interest. Brandt et al. (2014) offer helpful guidelines for convincing replications, and we encourage authors to read that article before undertaking a replication project. Authors should establish whether they are conducting a direct replication, which attempts to replicate as closely as possible a previously published experiment, or a conceptual replication, which attempts to extend the finding of one experiment into another domain. In both cases, only a high-powered design will provide sufficient evidence. We encourage authors to approach replications in a value-neutral way. If an experiment does not replicate it does not indicate that the results from the original experimental should now be considered invalid, and it certainly does not imply that the original research team did anything “wrong.”
Policy on prior publication
When authors submit manuscripts to this journal, these manuscripts should not be under consideration, accepted for publication or in press within a different journal, book or similar entity, unless explicit permission or agreement has been sought from all entities involved. However, deposition of a preprint on the author’s personal website, in an institutional repository, or in a preprint archive shall not be viewed as prior or duplicate publication. Authors should follow the Cambridge University Press Preprint Policy regarding preprint archives and maintaining the version of record.
Reporting Standards for Experimental Research
Papers that report on original experiments are recommended to follow the Reporting Standards for Experimental Research (Lab, Field, and Survey) devised by the Experimental Standards Committee of the American Political Science Association's Organized Section on Experimental Research, which can be found here.
Abstract and Keywords Preparation
For further guidance on how to prepare your Abstracts and Keywords, please refer to these guidelines.
How to prepare your materials for anonymous peer review
To ensure a fair and anonymous peer review process, authors should not allude to themselves as the authors of their article in any part of the text. This includes citing their own previous work in the references section in such a way that identifies them as the authors of the current work.
Please refer to our general guidelines on how to anonymize your manuscript prior to submission.
Tables and Artwork
Please refer to the following guidance about preparing artwork and graphics for submission.
Seeking permissions for copyrighted material
If your article contains any material in which you do not own copyright, including figures, charts, tables, photographs or excerpts of text, you must obtain permission from the copyright holder to reuse that material. Guidance on how to do that can be found here.
Competing Interests
All authors must include a competing interest declaration in their title page. This declaration will be subject to editorial review and may be published in the article.
Competing interests are situations that could be perceived to exert an undue influence on the content or publication of an author’s work. They may include, but are not limited to, financial, professional, contractual or personal relationships or situations.
If the manuscript has multiple authors, the author submitting must include competing interest declarations relevant to all contributing authors.
Example wording for a declaration is as follows: “Competing interests: Author 1 is employed at organisation A, Author 2 is on the Board of company B and is a member of organisation C. Author 3 has received grants from company D.” If no competing interests exist, the declaration should state “Competing interests: The author(s) declare none”.
Ethics and Transparency Policy Requirements
Please ensure that you have reviewed the journal’s Publishing ethics policies while preparing your materials.
Please review the Submitting Your Materials page for information on data availability requirements.
Authorship and contributorship
All authors listed on any papers submitted to this journal must be in agreement that the authors listed would all be considered authors according to disciplinary norms, and that no authors who would reasonably be considered an author have been excluded. For further details on this journal’s authorship policy, please see this journal's publishing ethics policies.
Author affiliations
Author affiliations should represent the institution(s) at which the research presented was conducted and/or supported and/or approved. For non-research content, any affiliations should represent the institution(s) with which each author is currently affiliated.
For more information, please see our author affiliation policy and author affiliation FAQs.
Funding statement
A declaration of sources of funding must be provided if appropriate. Authors must state the full official name of the funding body and grant numbers specified. Authors must specify what role, if any, their financial sponsors played in the design, execution, analysis and interpretation of data, or writing of the study. If they played no role this should be stated.
ORCID
We encourage authors to identify themselves using ORCID when submitting a manuscript to this journal. ORCID provides a unique identifier for researchers and, through integration with key research workflows such as manuscript submission and grant applications, provides the following benefits:
- Discoverability: ORCID increases the discoverability of your publications, by enabling smarter publisher systems and by helping readers to reliably find work that you have authored.
- Convenience: As more organisations use ORCID, providing your iD or using it to register for services will automatically link activities to your ORCID record, and will enable you to share this information with other systems and platforms you use, saving you re-keying information multiple times.
- Keeping track: Your ORCID record is a neat place to store and (if you choose) share validated information about your research activities and affiliations.
See our ORCID FAQs for more information. If you don’t already have an iD, you can create one by registering directly at https://ORCID.org/register.
ORCIDs can also be used if authors wish to communicate to readers up-to-date information about how they wish to be addressed or referred to (for example, they wish to include pronouns, additional titles, honorifics, name variations, etc.) alongside their published articles. We encourage authors to make use of the ORCID profile’s “Published Name” field for this purpose. This is entirely optional for authors who wish to communicate such information in connection with their article. Please note that this method is not currently recommended for author name changes: see Cambridge’s author name change policy if you want to change your name on an already published article. See our ORCID FAQs for more information.
English language editing services
Authors, particularly those whose first language is not English, may wish to have their English-language manuscripts checked by a native speaker before submission. This step is optional, but may help to ensure that the academic content of the paper is fully understood by the Editor and any reviewers.
In order to help prospective authors to prepare for submission and to reach their publication goals, Cambridge University Press offers a range of high-quality manuscript preparation services – including language editing – delivered in partnership with American Journal Experts. You can find out more on our Language Services page.
Please note that the use of any of these services is voluntary, and at the author's own expense. Use of these services does not guarantee that the manuscript will be accepted for publication, nor does it restrict the author to submitting to a Cambridge-published journal.
Author Hub
You can find guides for many aspects of publishing with Cambridge at Author Hub, our suite of resources for Cambridge authors.
Submission guidelines for pre-acceptance of registered reports
Registered reports are a form of results-blind review. The review process for traditional papers happens after the study has been completed and the data analyzed. To the extent that reviewers and editors lean too much on the results to judge the importance of a paper’s findings, it creates perverse incentives to publish positive results. In the traditional review process, registering pre-analysis plans makes research more transparent and more credible, but it does not change the way research is evaluated. Consequently, it does not fully resolve the problem.
Results-blind review addresses the problem by placing the beginning of the review process before researchers conduct an experiment (or set of experiments) and asking reviewers for an ex-ante evaluation of a proposed study’s novelty, importance, and quality. Registered reports that meet these high standards are “accepted in principle” and researchers are given the green light to conduct the study. After the study is conducted and the results are added to the registered report, the stage 2 review focuses on the execution of the experiment(s) and not the results.
Structure of a Registered Report
A registered report is a proposal for future research. At JEPS, an experiment would need to be the centerpiece of the research design. A registered report (RR) should consist of the following elements:
- Introduction that summarizes the research question.
- A brief literature review that summarizes previous research, making clear what gap(s) in the literature the proposed research will address.
- Clearly stated hypotheses as well as the theoretical basis for them.
- A detailed description of the proposed experimental design with all materials (e.g., scripts, question wording, etc.) placed in an appendix.
- A detailed explanation of how aspects of the experiment (design and measurement) relate to the hypotheses under investigation. If the plan proposes moderator(s), the author(s) should thoroughly explain how the moderator(s) will be measured. Statistical power should be discussed here.
- Detailed explanation of the methods that will be used to analyze the experimental data. This explanation should include information about how the author(s) will deal with missing values, the wording of manipulation checks, and whether and how any cases will be selected to be excluded from analysis. Author(s) should also explicitly state whether and how any covariates will be used, as well as how complex design features will be handled (e.g., through clustered standard errors, fixed effects, etc.). In an ideal case, the authors will be able to offer the exact code for the models they will run.
- A discussion of pilot data if any have been collected.
- Deposit in a registry (e.g., OSF, EGAP, etc.) after in-principle acceptance but before running the study.
Submissions that do not meet these criteria will be desk rejected.
We encourage authors to write the registered report as they would the manuscript and include placeholders for tables and anticipated figures. Simulated analyses may be presented in lieu of (or in addition to) pilot data.
Framework for the Review Process
RRs will be subject to a two-stage review process depicted in the figure below and described in more detail below.
Stage 1
Reviewers are asked to review the RR along five dimensions:
- Importance of the research question
- Soundness of proposed hypotheses
- Soundness and feasibility of proposed design (including statistical power)
- Whether proposed experiment offers an adequate and appropriate test of hypotheses
- Whether proposed methods are appropriate and sufficiently detailed
Like all manuscripts submitted to JEPS, AEs have the option of desk rejecting the PRR if they believe that it is fundamentally lacking on any of the five dimensions. RRs sent out for review will be handled in a similar way. The AE may conditionally accept the RR, ask for revisions, or reject it. AEs are encouraged to set a high bar for R&Rs. The proposed revisions should be doable and straightforward as well as promise to be reasonably successful at addressing reviewers’ concerns if taken seriously by the authors.
RRs that are conditionally accepted are subject to a second stage review where, to the extent possible, the original reviewers are re-contacted and asked to assess the manuscript along four dimensions listed below.
Stage 2
- Research question and rationale for hypotheses did not change from RR.
- Experimental procedures detailed in the RR were followed closely and any departures are noted and justified.
- Unregistered posthoc analyses are clearly labeled, justified, methodologically sound, and informative.
- Conclusions are justified by the data. (Considerations of data quality fall here.)
Reviewers are asked not to consider the perceived importance, novelty, or clarity of the empirical results.
If the reviewers and AE conclude that the manuscript did not adhere to the RR, the manuscript will be either rejected or, in the case that the AE deems a revision to be eminently doable, given a chance to make revisions.
Authors will be asked to agree at the outset of the review process that if their RR is conditionally accepted, they will continue to Stage 2 of the review process and ultimately publish their paper with JEPS if it clears the second stage.
RRs that are conditionally accepted will be given sufficient time to conduct the proposed experimental design, but likely no more than one year after conditional acceptance.
If unforeseen circumstances cause the authors to make major deviations to the design and protocol from the pre-accepted RR, authors are encouraged to reach out to the editorial office for guidance. AEs have the option of consulting with reviewers in the first stage.
Accepted PRRs must meet guidelines for publishing other manuscripts at JEPS.
Frequently Asked Questions
- What is the word limit and can I have an appendix?
- Can I conduct my proposed experiment(s) before or during the Stage 1 review?
- Can I report results from previous research, even if it wasn’t registered?
- Can I submit one aspect of a larger registered project as a standalone registered report?
- How detailed do I need to be when describing the research design?
- Should I simulate the results of my proposed experiment(s)?
- If my registered report is rejected, but I run the study anyway, can I submit it later as a traditional research article that features a pre-registered analysis plan?
- What if I need to make unforeseen adjustments once I am in the field?
- What if the results do not support my hypotheses?
- Can I conduct analyses that I did not register in the first stage of the review process?
- What if some of my analyses depend on the preliminary results?
- How do I avoid receiving a negative outcome after the Stage 2 review?
- Are there any resources I should consult before submitting a registered report?
What is the word limit and can I have an appendix?
The word limit depends on whether the RR is a Research Article (4,000 words), a Short Report (1,000), or a Replication (3,000). Authors are encouraged to use an online appendix as a way to provide details that reviewers need to evaluate proposed experimental designs.
Can I conduct my proposed experiment(s) before or during the Stage 1 review?
No. The proposed experiment(s) can only be conducted after the Stage 1 review process is complete and the proposed design reflects the reviewers’ comments.
Can I report results from previous research, even if it wasn't registered?
Yes. Previous research (registered or not) can be incorporated in a registered report in the same way it would be in a traditional paper — as a preliminary study in the main text or pilot study in the appendix. It is important that authors make clear in the text which results were registered and which were not.
Can I submit one aspect of a larger registered project as a standalone registered report?
Yes, but this should be made clear in the main text and an anonymized version of registered pre-analysis plan for the larger project should be provided in the online appendix, so that reviewers can consider the hypotheses to be tested in the registered report in the broader context of other proposed tests in the larger pre-analysis plan.
How detailed do I need to be when describing the research design?
As detailed as possible. Please use an appendix as a way to provide full details of experimental conditions, measures, and the like. Report everything that you would in a traditional paper, including power analyses, experimental stimuli, question wording, details about measurement (e.g., recoding, factor analysis, etc.), rationales for excluding data, details about statistical models, thresholds for inferential statistics, etc. See How does writing a registered report differ from a traditional research paper?
As is the case with a traditional paper, the burden is on the author(s) to organize the information in a clear and accessible way.
Should I simulate the results of my proposed experiment(s)?
While this is not required, it is an excellent habit. It will help diagnose potential issues with the proposed design and offer a way to more clearly communicate what the eventual paper will look like. Applications like Declare Design could be helpful in this regard (https://declaredesign.org/).
If my registered report is rejected, but I run the study anyway, can I submit it later as a traditional research article that features a registered analysis plan?
Yes. We recommend that the author(s) explain in the cover letter how the pre-analysis plan (and thus the study) was modified in light of reviews from Stage 1.
What if I need to make unforeseen adjustments once I am in the field?
You will need to note and justify in the main text of the registered report any divergences from the pre-analysis plan that was accepted in principle.
If unforeseen circumstances cause the authors to make major deviations to the design and protocol from the accepted-in-principle registered report, authors are encouraged to reach out to the editorial office for guidance. Associate Editors have the option of consulting with reviewers in the first stage.
What if the results do not support my hypotheses?
That is fine! The strength of your paper should rest on the importance of the research question and quality of the research design (assessed in Stage 1 of the review process), not the perceived novelty of the results.
Can I conduct analyses that I did not register in the first stage of the review process?
It is best to register all planned analyses. Nonetheless, if an additional analysis only becomes apparent after the experiment is conducted, it is permissible to do additional post-hoc analyses, as long as you offer a defensible substantive or statistical rationale for the additional analysis and flag these as post hoc when writing up the data analysis. One of the strengths of registered research is that it makes transparent the distinction between confirmatory and exploratory analyses.
What if some of my analyses depend on the preliminary results?
You may register contingencies in your pre-analysis plan (e.g., if A result is obtained, B method will be used).
How do I avoid receiving a negative outcome after the Stage 2 review?
Any divergences from the proposed pre-analysis plans that weaken the research design (e.g., reduce its power, vitiate the causal identification strategy, or alters the estimand) will likely lead to a negative outcome.
Are there any resources I should consult before submitting a registered report?
The Open Science Framework offers a number of resources, including checklists, for registered reports: https://cos.io/prereg/
Nosek, et al. (https://www.pnas.org/content/115/11/2600) offer helpful reflections on challenges to registered work in practice.
Declare Design help researchers formalize their research design and simulate data (https://declaredesign.org/).