Based on the prior write-up, describe any differences between the original and 1st replication in terms of methods, sample, sample size, and analysis. Note any potential problems such as exclusion rates, noisy data, or issues with analysis.
Methods
Power Analysis
How much power does your planned sample have for original effect? For an attenua
Planned sample size and/or termination rule, sampling frame, known demographics if any, preselection rules if any.
I plan to recruit at least 88 participants using prolific. This figure may change after power analyses are completed, however, seeing as this is a rescue attempt of a replication that may have failed largely due to a small sample size, I think it makes sense to plan for a sufficiently large sample. Participants who complete neither or only one of the two required experiment conditions will be removed from any analyses.
In the replication project, 91.3% of the sample had finished or attended college, so I will attempt to collect a sample that is more diverse in SES.
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.
“The scenes portrayed negative arousing or neutral objects placed on plausible neutral backgrounds. For each of 64 scenes (e.g., a car on a street), we created eight different versions by placing each of two similar neutral objects (e.g., two images of a car) and each of two related negative objects (e.g., two images of a car accident) on each of two plausible neutral backgrounds (e.g., two images of a street). An additional 32 scenes served as lures on a recognition memory test (Fig. 1). Participants in a previous study had rated the objects and backgrounds for valence and arousal, using 7-point scales (Kensinger, Garoff-Eaton, & Schacter, 2006). All negative objects had received arousal ratings of 5 to 7 (with high scores signifying an exciting or arousing image) and valence ratings lower than 3 (with low scores signifying a negative image). All neutral items (objects and backgrounds) had been rated as nonarousing (arousal values lower than 4) and neutral (valence ratings between 3 and 5).”
This will be followed precisely.
Fig. 1. “Examples of the scenes presented to subjects. Eight versions of each scene were created by combining each of four similar objects (two neutral objects, two negative and arousing emotional objects) with each of two plausible neutral backgrounds. In this example, the two neutral central objects are cars, and the two negative central objects are cars damaged in an accident; the neutral backgrounds are street scenes. Two of the eight versions of the completed scene are shown.” http://journals.sagepub.com/na101/home/literatum/publisher/sage/journals/content/pssa/2008/pssa_19_8/j.1467-9280.2008.02157.x/20160829/images/medium/10.1111_j.1467-9280.2008.02157.x-fig1.gif
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.
“Participants studied a set of 64 scenes (32 with a neutral object and 32 with a negative object, all on neutral backgrounds) for 5 s each, and then indicated on a 7-point scale whether they would approach or move away from the scene if they encountered it in real life. This task was used to maximize encoding.
After the delay period, participants performed an unexpected, self-paced recognition task. During this task, objects and backgrounds were presented separately and one at a time. Some of these objects and backgrounds were identical to the scene components that had been studied (e.g., the same car accident), others were the alternate version of the object or background and therefore shared the same verbal label but differed in specific visual details (e.g., a similar car accident), and others were objects or backgrounds that had not been studied (new). Participants never saw both the same and the similar version of an item at test. Each object or background was presented with a question (e.g., “Did you see a monkey?”). If the answer to the question was “yes,” participants pressed one button to indicate that the object or background was an exact match to a studied component (“same”) or a second button to indicate that it was not an exact match (“similar”). If the answer to the question was “no,” they pressed a third button.”
The recognition task includes 32 same objects (16 negative, 16 neutral), 32 similar objects (16 negative, 16 neutral), 32 new objects (16 negative, 16 neutral), 32 same backgrounds (16 previously shown with a negative object, 16 previously shown with a neutral object), 32 similar backgrounds (16 previously shown with a negative object, 16 previously shown with a neutral object), and 32 new backgrounds.”
This will be followed precisely. For the replication project, the experiment sessions before and after the delay period will be referred to as Session 1 and Session 2 respectively. I will also do this for my rescue attempt.
Controls
What attention checks, positive or negative controls, or other quality control measures are you adding so that a (positive or negative) result will be more interpretable?
Neither the original study, nor the replication controlled for sleep quality and number of hours slept, but I think it would be useful to control for this in the rescue attempt.
I also think it might be useful to periodically check with participants whether they actually find some of the stimuli to be negatively or neutrally arousing, which was the intention of the creators of the stimuli. After looking through the images that make up the stimulus set, whilst some of them may induce negative affect, some seemed too unrealistic to induce negative affect, or just seemed like they would stand out as being strange rather than negative (potentially due to appearing poorly photoshopped). This might need to be done with a separate set of participants in a different experiment.
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.
“We scored a response as specific recognition of visual details when a subject correctly responded”same” to a same item, but as general recognition without specific details when a subject responded “similar” to a same item. Because “similar” responses were constrained by the number of “same” responses (i.e., subjects responded “similar” only when they did not remember the visual details), we computed the general recognition score as the proportion of “similar” responses after exclusion of “same” responses (similar/[1- same]).” “Specific and general recognition scores were computed separately for central objects (negative or neutral) and for the peripheral neutral backgrounds (studied with either a negative or a neutral object).”
I will follow the replication, which planned to perform a 2 (condition: sleep, wake) x 2 (valence: negative, neutral) x 2 (scene component: object, background) mixed ANOVA. As well as a follow-up 2 (condition: sleep, wake) x 2 (valence: negative, neutral) mixed ANOVA applied on the recognition of objects and backgrounds separately.
Time and funds permitting, I also plan to do additional analyses double checking the valence ratings of the stimulus, as well as whether sleep quality (low, medium, high) has any potential interaction effect.
The term of interest is the three-way interaction (Condition x Valence x Scene Component). The original study found that negative, but not neutral stimuli were better remembered after sleep than wake. The original replaction did not find this result.
Differences from Original Study and 1st replication
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.
Key Differences
- I aim to recruit a sample greater than that of the original study (n = 88) and the first replication (n = 23) - I intend to recruit a sample diverse in SES - Participants will be randomly assigned to one of the two conditions (sleep or wake), rather than assigning themselves to a condition - The original study was done in-person, and replication was done online using Mturk workers. I will do my rescue online using prolific workers - I plan to run a smaller parallel study confirming the valence ratings of the stimuli by the original authors - I plan to ask participants in all conditions about their sleep quality the previous night when they complete the second of the two experimental sessions - I plan to include sleep quality in an additional mixed ANOVA. This may result in a slight change to the original claims of the article, which were that sleep preferentially enhances memory for emotional components of scenes. A novel result for this control would result in a new claim: Depending on sleep quality, sleep preferentially enhances memory for emotional components of scenes
Methods Addendum (Post Data Collection)
Actual Sample
I will be collecting data from 88 participants, which was the number of participants studied in the original paper.
Differences from pre-data collection methods plan
Any differences from what was described as the original plan, or “none”.