Replication of Study X by Sample & Sample (20xx, Psychological Science)

Introduction

My research interests are in cognitive development, particularly in how children acquire language and concepts. However, for this class and considering the scope of the project, I am aiming to conduct an online study with adult participants, which meant I was going to do something a little different from my primary research interests. More generally, I am interested in the relationship between language and cognition and how this interplay is seen in online language processing. I teamed up with several other first-year Psych PhDs to find an article that fit all of our interests and found this article on the Moses effect, which I find fascinating since a simple manipulation affecting the readibility of the sentence influences the result and leads people to a fallacy in processing and judgment.

The stimuli and procedure for this study will be relatively simple. We will likely use Qualtrics to design the experiment. There will be an instruction slide telling participants that they will answer trivia questions and how to respond accordingly. Then, there will be one control question followed by the question of interest in which there is a distortion (asking how many of each animal Moses, instead of Noah, brought on the ark). We will make two conditions, one in which the font will be easy to read and one in which the font is harder to read. My experience with Qualtrics is limited, so getting the hang of it and implementing things like multiple conditions and randomization of participants to the two conditions could be challenging.

Here is the link to the repo: https://github.com/kostaboskovic/song2008/

Here is the link to the original paper: https://github.com/kostaboskovic/song2008/blob/main/original_paper/SongSchwartz.pdf

Methods

Power Analysis

Original effect size, power analysis for samples to achieve 80%, 90%, 95% power to detect that effect size. Considerations of feasibility for selecting planned sample size.

Planned Sample

Planned sample size and/or termination rule, sampling frame, known demographics if any, preselection rules if any.

Materials

All materials - can quote directly from original article - just put the text in quotations and note that this was followed precisely. Or, quote directly and just point out exceptions to what was described in the original article.

Procedure

Can quote directly from original article - just put the text in quotations and note that this was followed precisely. Or, quote directly and just point out exceptions to what was described in the original article.

Analysis Plan

Can also quote directly, though it is less often spelled out effectively for an analysis strategy section. The key is to report an analysis strategy that is as close to the original - data cleaning rules, data exclusion rules, covariates, etc. - as possible.

Clarify key analysis of interest here You can also pre-specify additional analyses you plan to do.

Differences from Original Study

Explicitly describe known differences in sample, setting, procedure, and analysis plan from original study. The goal, of course, is to minimize those differences, but differences will inevitably occur. Also, note whether such differences are anticipated to make a difference based on claims in the original article or subsequent published research on the conditions for obtaining the effect.

Methods Addendum (Post Data Collection)

You can comment this section out prior to final report with data collection.

Actual Sample

Sample size, demographics, data exclusions based on rules spelled out in analysis plan

Differences from pre-data collection methods plan

Any differences from what was described as the original plan, or “none”.

Results

Data preparation

Data preparation following the analysis plan.

Confirmatory analysis

The analyses as specified in the analysis plan.

Side-by-side graph with original graph is ideal here

Exploratory analyses

Any follow-up analyses desired (not required).

Discussion

Summary of Replication Attempt

Open the discussion section with a paragraph summarizing the primary result from the confirmatory analysis and the assessment of whether it replicated, partially replicated, or failed to replicate the original result.

Commentary

Add open-ended commentary (if any) reflecting (a) insights from follow-up exploratory analysis, (b) assessment of the meaning of the replication (or not) - e.g., for a failure to replicate, are the differences between original and present study ones that definitely, plausibly, or are unlikely to have been moderators of the result, and (c) discussion of any objections or challenges raised by the current and original authors about the replication attempt. None of these need to be long.