'Online knowledge revision study 1'
(AsPredicted #100,923)
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1) Have any data been collected for this study already?
No, no data have been collected for this study yet.

2) What's the main question being asked or hypothesis being tested in this study?
This study is related to "Online Study Stories 1" (see as.predicted file #75834).
This study investigates how pictures potentially influence knowledge revision processes during reading. Therefore, we will use 16 text passages introduced by O'Brien, Cook, & Guéraud (2010) and vary whether these text passages are presented without pictures or with pictures. The text passages exist in a consistent version and an outdated (also called qualified) version. In the consistent version, participants read information that is consistent with a subsequent target sentence. In the outdated version, participants first read information that is inconsistent with a subsequent target sentence but that is revised before the target sentence is presented. This means that participants must revise earlier information in the outdated version to make the target sentence consistent. As dependent variable, reading time for the target sentence will be measured.
We hypothesize a significant interaction effect between the factors text version (only consistent information vs. outdated information) and picture (text is presented without pictures vs. text is presented with pictures). We expect no difference in the reading time for the target sentences as a function of the factor picture for the consistent version. For the outdated version, we expect faster reading times for the target sentences if the text is presented with a picture compared to if the text is presented without a picture.

3) Describe the key dependent variable(s) specifying how they will be measured.
Reading time for the target sentence in milliseconds.

4) How many and which conditions will participants be assigned to?
There are four within-subjects conditions resulting from crossing the factor text version (only consistent information vs. outdated information) and the factor picture (text presentation without pictures vs. with pictures).
We will use four lists of texts containing one version of each text to counterbalance the different versions. Every list consists of 4 texts with consistent information presented without pictures, 4 texts with outdated information presented without pictures, 4 texts with consistent information presented with pictures, and 4 texts with outdated information presented with pictures. Within each list, the order of texts is randomized. Participants are randomly assigned to one of these 4 lists.

5) Specify exactly which analyses you will conduct to examine the main question/hypothesis.
Reading time for the target sentences will be analyzed with a linear mixed effects model. Text passages (items) and participants will be included as random effects, text version (consistent information vs. outdated information), and picture (without vs. with) will be included as fixed effects. If the interaction of text version * picture is significant, pairwise single comparisons will be conducted to test whether reading time differs for the factor picture within each level of text version. We will also test whether reading time differs for the factor text version within each level of picture.
Further, in case that the interaction is not significant, we will run additional analyses to test whether the single comparisons reach significance.
We will run additional analyses to test whether we were able to replicate the outdated-information effect without pictures reported by O'Brien et al. (2010).

6) Describe exactly how outliers will be defined and handled, and your precise rule(s) for excluding observations.
Exclusions of participants: Participants who do not agree to have their data processed will be deleted. Participants who do not speak English fluently or who report serious technical issues during participation will be excluded. Moreover, after every text, participants have to answer a yes-no comprehension question about text's content. After all 16 texts, participants complete an old/new picture memory task. Participants with 6 or more wrong answers in the comprehension questions and/or 6 or more wrong answers in the picture memory task (equals ca. 40%) will be excluded.

Exclusion of target sentences: Per participants, target sentences with a reading time below 500ms or above 7000ms will be excluded.

7) How many observations will be collected or what will determine sample size?
No need to justify decision, but be precise about exactly how the number will be determined.
We aim for 400 participants. Due to possible exclusion of participants, we will assess 450 participants.
We conducted a power analysis for the interaction effect of the factors text version and picture. Parameters were estimated based on data reported in O'Brien et al. (2010) and on data from previous studies (see as.predicted #75834, #79275, & #81719).
With 400 participants, we can detect an interaction effect of -120ms with sufficient power (1-β >/= .8).
The parameters were set as follows:
Fixed effects (dummy coding: text version: consistent = 0, outdated = 1; Picture: not present = 0, present = 1): estimate intercept = 1900, estimate text version = 130, estimate picture = -20, estimate consistency*picture= -120.
SD of random effects: SD participant = 600, SD text version = 250, SD residual = 850

8) Anything else you would like to pre-register?
(e.g., secondary analyses, variables collected for exploratory purposes, unusual analyses planned?)
Participants will be recruited via Prolific. Screening criteria will be previous study-participation (no participation in the studies "Stories 1" (#75834), "Stories 2" (#79275), or "Stories 3" (#81719)), language (first language = English, English as a fluent language), no language-related disorder, current country of residence (United States of America), and age (between 18 and 35).
Additional analysis:
As an exploratory analysis, we will examine the reading times for the sentence that follows the target sentence (i.e., spill-over sentence). For this analysis we will exclude spill-over sentences with a reading time below 500ms or above 7000ms per participant. Additionally, we will exclude spill-over sentences that follow after excluded target sentences. We will compute another linear mixed effects model with text passages (items) and participants as random effects, text version (consistent information vs. outdated information), and picture (without vs. with) as fixed effects.
We will also analyze whether the error rate for the comprehension questions varies as a function of text version. If so, we may increase the allowed error rate.
Moreover, we will check whether the processing time for sentences varies as a function of picture presentation. Therefore, we will compare those sentences presented with a picture in the condition with pictures to the same sentences in the condition without pictures. We expect longer processing times for sentences provided with pictures compared to sentences without pictures.