Overview

Project goals

The goals of this project are to establish:

  1. if children and adults generalize from a sample to a social group from a sample that is, unbeknownst to them, structurally skewed, resulting in inaccurate beliefs about the group

  2. if children and adults can adjust their generalization from a sample to a social group to account for the fact that the sample was skewed by a structural process

This study focuses on question (2) in adults.

Study goals

The primary goal of this study was to see if, given evidence of that a sample was skewed, adults adjust their inferences about a social population to account for the skew.

Adults were shown the exact same sample of novel group members (Zarpies), but the sample was either not skewed (Zarpies were sampled without any being turned away) or skewed (many additional Zarpies were turned away during the sampling process). Adults were then asked to estimate the average height of the same and the average height of the population.

Adults in the critical occluded conditions did not observe the heights of Zarpies in the population, but were able to hear/see the success/failure of the sampling process. As controls for a potential null result, separate groups of adults in visible conditions observed the heights of Zarpies during the sampling process (i.e., that they were the same height, or that they were much taller).

Results

This study confirmed our pre-registered hypothesis that adults are capable of adjusting their inferences about a social population against structural skew, although this might be weakened by some caveats from exploratory findings.

  • Pre-registered: As expected if adults are able to adjust, adults made different population inferences when the sample was skewed versus not skewed, in both occluded and visible sets of conditions. (see population inference).

    • Exploratory: However, this adjustment was counteracted in the critical occluded skewed condition by the fact that adults also made inflated estimates of the sample in this condition (and only this condition), even though the sample was the same in both conditions. (see sample representation).
    • Exploratory: As a result, in the critical occluded skewed condition, adults did not respond significantly differently when asked about the population compared to the sample; both were inflated relative to the true sample mean. (see sample vs population).
  • Pre-registered: As expected if adults are able to adjust, adults were more likely to report that the population is taller than the sample and less likely to report that the population is the same in height as the sample in the skewed conditions compared to the not skewed conditions, in both occluded and visible sets of conditions.

    • Exploratory: However, even in the skewed conditions, the population is “the same” as the sample was a very common response.

Alternative hypotheses we can rule out:

  1. Adults fail to adjust their generalization from sample to population against structural skew, instead just generalizing directly off the sample, unless they have direct population information.

    • Inconsistent with the facts that both population inferences and explicit reports varied in occluded skewed vs not skewed conditions (pre-registered results).
    • Consistent with the fact that adults didn’t make significantly different responses for sample vs population in the critical occluded skewed condition (an exploratory null result).
    • Left unexplained is the fact that sample estimates were significantly higher in the occluded skewed condition only.
  2. Adults are guessing and don’t understand the paradigm.

    • Inconsistent with the skewed vs not skewed effects in both visible and occluded sets of conditions.

Alternative hypotheses/twists on the main hypothesis that could still be in play:

  1. Adults fail to adjust their generalization from sample to population against structural skew, instead generalizing in a way weighted by visual salience/attention (e.g., the scrunching/unscrunching Zarpies in the shorter boat condition).

    • Consistent with the skewed vs not skewed effects in the occluded conditions: adults adjusted their population estimates upward when they heard/saw the sampled Zarpies scrunch/unscrunch.
      • Would need to run a follow-up with a not skewed condition involving a short boat, where the same sample boards, 2 scrunch, but none are turned away.
    • Left unexplained is the fact that sample estimates were significantly higher in the occluded skewed condition only.
  2. Adults are able to make adjustments against structural skew, but adjust too much, adjusting both their sample and population estimates. This would require adults’ representation of the sample to be contaminated by their representation of the population (e.g., by an expectation that samples should be representative).

    • Consistent with the fact that sample estimates were significantly higher in the occluded skewed condition only: adults adjusted their sample estimates to correspond with what they expected from the population/sampling information.

    • However, inconsistent with the fact that adults were more likely to explicitly report that the population is taller than the sample in the skewed condition than the not skewed condition.

Methods

The study was preregistered on OSF.

Participants

Data was collected from 399 adults recruited via Prolific on Mon 8/18/2025. Participants were required to be in the United States, fluent in English, and have not participated in any pilots of this study.

Participants were paid $2.75 for an estimated 10-12 minute task. In fact, the study generally took about 10 minutes for participants.

The final sample included 381 adults (n = 85-107 in each of the 4 conditions).

boarding participants
visible
not skewed 85
skewed 107
occluded
not skewed 103
skewed 86

Exclusion criteria

18 participants (4.5% of all participants) were excluded for meeting at least 1 of the following exclusion criteria:

  • failing the sound check (n = 0 participants)

  • failing to select the correct task description (i.e., did not select “Watching videos about fictional people from an island”) (n = 4 participants)

  • failing the memory check (n = 10 participants)

  • failing the comprehension check (n = 5 participants)

Note that participants who did not respond to the comprehension check were included in the final sample. Excluding them does not change the below results.

Memory check

Participants overwhelmingly passed the memory check for the Quaffa boarding sequence, i.e., “no”, not all the Quaffas made it onto the boat.

Participants who made incorrect responses were excluded.

Comprehension check

Participants overwhelmingly passed the comprehension check for the Zarpie boarding sequence. Note the correct answer to this question depends on condition:

  • In the skewed condition, the correct answer is “no”, not all of the Zarpies made it onto the boat.

  • In the not skewed condition, the correct answer is “yes”, all of the Zarpies made it onto the boat.

Note that there are some non-responses (NAs), because I forgot to require a response on this question in Qualtrics. These participants were included below, but excluding them does not change anything.

Demographics

This study recruited a sample representative of the US on sex, age, and ethnicity (simplified US Census categories), using the representative sample feature on Prolific.

age
mean sd n
46.10 15.76 381
  • The sample was largely young and middle-aged.
gender n prop
Female 190 49.9%
Male 184 48.3%
Non-binary 5 1.3%
Prefer not to specify 2 0.5%
  • The sample was diverse in terms of gender identities in the US.
race n prop
White, Caucasian, or European American 233 61.2%
Black or African American 42 11.0%
Hispanic or Latino/a 24 6.3%
White, Caucasian, or European American,Hispanic or Latino/a 20 5.2%
South or Southeast Asian 12 3.1%
East Asian 9 2.4%
White, Caucasian, or European American,Black or African American 8 2.1%
Native American, American Indian, or Alaska Native 4 1.0%
Prefer not to specify 4 1.0%
Middle Eastern or North African 3 0.8%
White, Caucasian, or European American,East Asian 3 0.8%
White, Caucasian, or European American,Native American, American Indian, or Alaska Native 3 0.8%
South or Southeast Asian,East Asian 2 0.5%
White, Caucasian, or European American,Black or African American,Native American, American Indian, or Alaska Native 2 0.5%
White, Caucasian, or European American,Middle Eastern or North African 2 0.5%
American Citizen 1 0.3%
Black or African American,Native American, American Indian, or Alaska Native 1 0.3%
Hispanic or Latino/a,Black or African American 1 0.3%
Hispanic or Latino/a,South or Southeast Asian 1 0.3%
Indigenous American 1 0.3%
White, Caucasian, or European American,East Asian,Native Hawaiian or other Pacific Islander 1 0.3%
White, Caucasian, or European American,Native Hawaiian or other Pacific Islander 1 0.3%
White, Caucasian, or European American,South or Southeast Asian 1 0.3%
White, Caucasian, or European American,South or Southeast Asian,Native Hawaiian or other Pacific Islander,Prefer not to specify 1 0.3%
White, Caucasian, or West Asian American (Iranian/Persian) 1 0.3%
  • The sample was also racially diverse.
education n prop
Less than high school 3 0.8%
High school/GED 56 14.7%
Some college 115 30.2%
Bachelor's (B.A., B.S.) 151 39.6%
Master's (M.A., M.S.) 40 10.5%
Doctoral (Ph.D., J.D., M.D.) 15 3.9%
Prefer not to specify 1 0.3%
  • The sample was about evenly split in whether they had attained a college degree or not.

Procedure

This study was administered as a Qualtrics survey, and approved by the NYU IRB (IRB-FY2024-9169).

After providing their consent, participants completed a captcha and sound check, and were asked to watch videos sound on. Participants then watched the following videos in order:

  1. In the prior setting and familiarization phase, participants saw a photorealistic picture of 5 human adults and then another picture of a different 5 adults appear on screen against a grid. These adults were all 10 gridline units tall.
Prior setting and familiarization.
Prior setting and familiarization.
  1. In the boat training phase, participants were shown a parade of fictional animals attempting to board the boat, to illustrate how the boat works. In the skewed condition, the boat was 6 units tall. In the not skewed condiiton, the boat was 10 units tall.

    • The boat height was specified to be accidental (“When the boat builders were building the boat, they started building the boat from the bottom, but ran out of the special wood they needed for the boat! So the boat ended up being this tall. It might be hard for anyone who is taller than the boat to get on the boat.”), to avoid any justificatory reasoning about the height of the boat being informative about the height of Zarpies or vice versa.

    • To communicate how the boat functions to exclude those shorter than the boat, participants then watched a parade of 20 fictional animals (Quaffas, taken from Foster-Hanson et al., 2019) attempt to board the boat, one at a time, from shortest to tallest.

    • The height of animals were scaled to the height of the boat, such that 10 animals were always shorter than the boat (these animals boarded successfully) and 10 animals were always taller than the boat (all but one were unable to board; the third quaffa successfully boards by bending its head).

    Quaffas in the skewed condition. Note the Quaffas are short, since the skewed condition involves a short boat.
    Quaffas in the skewed condition. Note the Quaffas are short, since the skewed condition involves a short boat.
    • Participants were asked a memory check: “Did all of the animals board the boat?” (yes/no), and received an affirmation (if they said “no”) or correction (if they said “yes”).
  2. In the boat boarding phase, participants learned that Zarpies live on Zarpie island, and saw an island with many Zarpies overhead. Participants learned that all the grownup Zarpies’ names were put into a hat, and some of their names “were drawn out of a hat to try and visit us”. Participants saw then saw a parade of Zarpies attempt to board the boat to visit us, one at a time. Participants were told that they were all grown-up Zarpies.

    • In the occluded condition, the heights of Zarpies were hidden behind a curtain that showed only their feet. Boarding in occluded not skewed condition.

    • In the visible condition, the heights of Zarpies were visible.

    • In the not skewed condition, the boat is 10 units tall. 6 Zarpies attempt to board, all of whom successfully make it on (6 out of 6 successful = 100% successful). Of the 6 who board, none had to stoop to board.

    Boarding in visible not skewed condition.
    Boarding in visible not skewed condition.
    • In the skewed condition, the boat is 6 units tall. 20 Zarpies attempt to board, 6 of whom successfully make it on (6 out of 16 successful = 30% successful). Of the 6 who make it on, 2 had to stoop to board.
    Boarding in visible skewed condition.
    Boarding in visible skewed condition.
  3. After the boat boarding phase, participants were asked a comprehension check: “Did all of the Zarpies board the boat?” (yes/no), and received either an affirmation (if they said “no” in the skewed condition, or “yes” in the not skewed condition) or correction (if they said “yes” in the skewed condition, or “no” in the not skewed condition).

  • Note: I forgot to turn on validation to force a response, so there are quite a few non-responses to this question. These people were retained in the following analyses.
  1. In the sample observation phase, all participants saw the Zarpies who successfully boarded the boat get off the boat to visit us. The Zarpies got off one at a time, and each waved/descrunched if relevant. The height of this observed sample (4, 5, 6, 6, 7, 8) was held constant across conditions.

    • To emphasize the height of the Zarpies relative to the boat, participants watched Zarpies deboard the boat, wave, reboard the boat (with any Zarpies taller than the boat stooping down again to board again), and deboard again (with any Zarpies taller than the boat straightening up again).
Observed sample in skewed condition. Note the observed sample is the same, but the height of the boat is short in the skewed condition, vs tall in the not skewed condition.
Observed sample in skewed condition. Note the observed sample is the same, but the height of the boat is short in the skewed condition, vs tall in the not skewed condition.

Participants were asked the following DVs in the following order:

  1. Participants were asked the average height of the Zarpies who visited (Sample representation) and the average height of Zarpies on Zarpie island (Population inference), in counterbalanced order.

  2. Participants were then asked an explicit comparison question asking them to compare the heights of Zarpies on Zarpie island to that of Zarpies who visited: shorter, about the same, or taller (see explicit comparison).

Finally, participants were asked for any problems or confusion they had, what they thought the task was about (see [Participant feedback]), and demographic information.

Primary results

Sample representation

As a check that they could retrieve the mean of the sample they observed, participants were asked, “Which picture shows the average height of the Zarpies who visited?”, and had to choose between a Zarpie of height 4, 5, 6, 7, or 8.

We did not preregister any results on this measure.

Sample representation question in the skewed condition, with the response options in red boxes.
Sample representation question in the skewed condition, with the response options in red boxes.

Since all participants saw the same sample, participants should provide the same response, regardless of condition. The sample was (4, 5, 6, 6, 7, 8), so the the response is expected to be the mean of the sample, which is 6 (indicated with red dots below).

Unexpectedly, there was an interaction between the population occluded/visible and boarding skewed/not skewed conditions, such that in the occluded condition only, such that those in the skewed sample condition reported taller estimates of the sample than those in the not skewed sample condition. (t = 2.95, p = 0.004). This was unexpected, since both conditions observed the same sample.

In the occluded skewed condition, participants on average reported taller heights than the true mean of the sample, which is 6 (t(85) = 4.3, p < .001), while participants were accurate and not significantly different from the true mean in all of the other three conditions.

Population inference

To assess how tall participants thought Zarpies in general are, participants were asked: “Which picture shows the average height of Zarpies on Zarpie island?” Response options were a Zarpie of height 4, 5, 6, 7, or 8.

Population representation question in the skewed condition, with the response options in red boxes.
Population representation question in the skewed condition, with the response options in red boxes.

We pre-registered that if participants adjust their inferences about the population based on biases in the sampling process:

  • Participants in the not skewed condition should infer that the population is like the sample, since everyone was able to board, so they should respond with something similar to sample mean, i.e., 6.
  • Participants in the skewed condition should infer the population is taller than the sample, since Zarpies taller than the boat were unable to board, so they should report significantly taller height than those in the unrestricted condition.

In the occluded condition, participants reported the population was taller in the skewed condition than the not skewed condition (t = 3.97, p < .001), consistent with adjustment against skew. In the visible condition, participants reported the population was taller in the skewed condition than the not skewed condition (t = 5.18, p < .001), consistent with the actual height difference between the populations they each saw.

In the visible not skewed condition, participants’ population inferences were no different from 6, the actual population mean (t(84) = 1.3, p = 0.198).

In contrast, in the visible skewed condition, participants’ population inferences were significantly shorter than 8, the actual population mean (t(106) = -21.39, p < .001).

Explicit comparison

Participants were explicitly asked to compare the population to the sample: “Do you think the Zarpies on Zarpie island are shorter, the same, or taller in height than the Zarpies who visited?”

We pre-registered that if adults do adjust, they should be more likely to say “taller” in the skewed condition than the not skewed condition for both the visible and occluded sets of conditions.

Notably, “the same” is an extremely common response across all conditions.

population boarding shorter the same taller
visible not skewed 4% 86% 11%
visible skewed 9% 43% 48%
occluded not skewed 3% 89% 8%
occluded skewed 6% 55% 40%

Participants’ explicit comparisons were significantly different between conditions (p < .001, Fisher’s exact).

## 
## Call:
## glm(formula = dv_comp_taller ~ boarding, family = binomial, data = .)
## 
## Coefficients:
##                Estimate Std. Error z value       Pr(>|z|)    
## (Intercept)     -2.4744     0.3681  -6.721 0.000000000018 ***
## boardingskewed   2.0496     0.4291   4.776 0.000001789462 ***
## ---
## Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
## 
## (Dispersion parameter for binomial family taken to be 1)
## 
##     Null deviance: 200.23  on 188  degrees of freedom
## Residual deviance: 171.67  on 187  degrees of freedom
## AIC: 175.67
## 
## Number of Fisher Scoring iterations: 5
## 
## Call:
## glm(formula = dv_comp_same ~ boarding, family = binomial, data = .)
## 
## Coefficients:
##                Estimate Std. Error z value        Pr(>|z|)    
## (Intercept)      2.1239     0.3190   6.658 0.0000000000278 ***
## boardingskewed  -1.9373     0.3856  -5.024 0.0000005057386 ***
## ---
## Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
## 
## (Dispersion parameter for binomial family taken to be 1)
## 
##     Null deviance: 218.39  on 188  degrees of freedom
## Residual deviance: 188.47  on 187  degrees of freedom
## AIC: 192.47
## 
## Number of Fisher Scoring iterations: 4
## 
## Call:
## glm(formula = dv_comp_shorter ~ boarding, family = binomial, 
##     data = .)
## 
## Coefficients:
##                Estimate Std. Error z value      Pr(>|z|)    
## (Intercept)     -3.5066     0.5859  -5.984 0.00000000217 ***
## boardingskewed   0.7215     0.7454   0.968         0.333    
## ---
## Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
## 
## (Dispersion parameter for binomial family taken to be 1)
## 
##     Null deviance: 66.253  on 188  degrees of freedom
## Residual deviance: 65.281  on 187  degrees of freedom
## AIC: 69.281
## 
## Number of Fisher Scoring iterations: 6

In the occluded condition, participants were more likely to say that Zarpies on Zarpie island are “taller” and less likely to say “the same” compared to Zarpies who visited, in the skewed condition compared to the not skewed condition. Responses that they are “shorter” were rare and did not differ across conditions.

## 
## Call:
## glm(formula = dv_comp_taller ~ boarding, family = binomial, data = .)
## 
## Coefficients:
##                Estimate Std. Error z value      Pr(>|z|)    
## (Intercept)     -2.1335     0.3525  -6.052 0.00000000143 ***
## boardingskewed   2.0400     0.4021   5.073 0.00000039218 ***
## ---
## Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
## 
## (Dispersion parameter for binomial family taken to be 1)
## 
##     Null deviance: 238.50  on 191  degrees of freedom
## Residual deviance: 205.53  on 190  degrees of freedom
## AIC: 209.53
## 
## Number of Fisher Scoring iterations: 4
## 
## Call:
## glm(formula = dv_comp_same ~ boarding, family = binomial, data = .)
## 
## Coefficients:
##                Estimate Std. Error z value      Pr(>|z|)    
## (Intercept)      1.8056     0.3115   5.796 0.00000000678 ***
## boardingskewed  -2.0878     0.3676  -5.679 0.00000001357 ***
## ---
## Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
## 
## (Dispersion parameter for binomial family taken to be 1)
## 
##     Null deviance: 255.04  on 191  degrees of freedom
## Residual deviance: 215.43  on 190  degrees of freedom
## AIC: 219.43
## 
## Number of Fisher Scoring iterations: 4
## 
## Call:
## glm(formula = dv_comp_shorter ~ boarding, family = binomial, 
##     data = .)
## 
## Coefficients:
##                Estimate Std. Error z value     Pr(>|z|)    
## (Intercept)     -3.3081     0.5878  -5.628 0.0000000183 ***
## boardingskewed   1.0360     0.6752   1.534        0.125    
## ---
## Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
## 
## (Dispersion parameter for binomial family taken to be 1)
## 
##     Null deviance: 95.105  on 191  degrees of freedom
## Residual deviance: 92.397  on 190  degrees of freedom
## AIC: 96.397
## 
## Number of Fisher Scoring iterations: 6

In the visible condition, same results.

Secondary results

Sample vs population

As an implicit comparison, we can compare each participant’s sample representation and population inference to each other.

## 
## Call:
## lm(formula = response ~ boarding * dv, data = data_tidy %>% filter(population == 
##     "occluded"))
## 
## Residuals:
##      Min       1Q   Median       3Q      Max 
## -2.38372 -0.23256 -0.04854 -0.03883  1.96117 
## 
## Coefficients:
##                          Estimate Std. Error t value            Pr(>|t|)    
## (Intercept)              6.048544   0.051023 118.544 <0.0000000000000002 ***
## boardingskewed           0.184014   0.075640   2.433              0.0155 *  
## dvdv_pop                -0.009709   0.072158  -0.135              0.8930    
## boardingskewed:dvdv_pop  0.160872   0.106971   1.504              0.1335    
## ---
## Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
## 
## Residual standard error: 0.5178 on 374 degrees of freedom
## Multiple R-squared:  0.06995,    Adjusted R-squared:  0.06249 
## F-statistic: 9.376 on 3 and 374 DF,  p-value: 0.000005457

Within the occluded condition, there is no interaction between the boarding condition (skewed vs not skewed) and the DV (sample vs pop), suggesting participants in the skewed condition did not generalize from sample to population differently than participants in the not skewed condition.

In each of the not skewed conditions, participants did not give different responses to sample and population questions (occluded not skewed: t(102) = 0.3, p = 0.765, visible not skewed: t(84) = 0.35, p = 0.726). This is expected since in the not skewed conditions, the sample and the population are identical.

In the visible skewed condition, participants gave taller responses to the population than to the sample question (t(106) = -6.83, p < .001). This is expected since in the visible skewed condition, the population is observed to be taller than the sample.

In the occluded skewed condition, participants did not give different responses to the population versus sample questions (t(85) = -1.58, p = 0.118). This suggests that participants may not have adjusted their generalization from the sample based on the sampling process they observed.

Sample vs population by explicit comparison

Order effects

Participants saw the two DVs in counterbalanced order:

  • pop_sample = population DV first, then sample DV
  • sample_pop = sample DV first, then population DV

There were no order effects on any of the three DVs.

Sample representation order effects

The interaction between conditions on the sample representation was consistent, regardless of DV order.

## Anova Table (Type II tests)
## 
## Response: dv_sample
##                                Sum Sq  Df F value   Pr(>F)   
## population                      0.930   1  4.1661 0.041945 * 
## boarding                        0.227   1  1.0162 0.314068   
## cb_dvorder                      0.068   1  0.3058 0.580585   
## population:boarding             1.637   1  7.3349 0.007074 **
## population:cb_dvorder           0.021   1  0.0926 0.761078   
## boarding:cb_dvorder             0.015   1  0.0672 0.795566   
## population:boarding:cb_dvorder  0.176   1  0.7898 0.374728   
## Residuals                      83.237 373                    
## ---
## Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1

Population inference order effects

There is no effect of DV order or interaction with DV order on population representations.

## 
## Call:
## lm(formula = dv_pop ~ population * boarding * cb_dvorder, data = data)
## 
## Residuals:
##      Min       1Q   Median       3Q      Max 
## -2.26829 -0.26829 -0.04839 -0.02273  1.97727 
## 
## Coefficients:
##                                                         Estimate Std. Error
## (Intercept)                                             6.022727   0.090233
## populationoccluded                                      0.001663   0.129922
## boardingskewed                                          0.426548   0.115472
## cb_dvordersample_pop                                    0.074834   0.129922
## populationoccluded:boardingskewed                      -0.182646   0.175526
## populationoccluded:cb_dvordersample_pop                -0.050837   0.177188
## boardingskewed:cb_dvordersample_pop                     0.107470   0.177480
## populationoccluded:boardingskewed:cb_dvordersample_pop  0.089129   0.250427
##                                                        t value
## (Intercept)                                             66.747
## populationoccluded                                       0.013
## boardingskewed                                           3.694
## cb_dvordersample_pop                                     0.576
## populationoccluded:boardingskewed                       -1.041
## populationoccluded:cb_dvordersample_pop                 -0.287
## boardingskewed:cb_dvordersample_pop                      0.606
## populationoccluded:boardingskewed:cb_dvordersample_pop   0.356
##                                                                    Pr(>|t|)    
## (Intercept)                                            < 0.0000000000000002 ***
## populationoccluded                                                 0.989794    
## boardingskewed                                                     0.000254 ***
## cb_dvordersample_pop                                               0.564968    
## populationoccluded:boardingskewed                                  0.298752    
## populationoccluded:cb_dvordersample_pop                            0.774341    
## boardingskewed:cb_dvordersample_pop                                0.545193    
## populationoccluded:boardingskewed:cb_dvordersample_pop             0.722109    
## ---
## Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
## 
## Residual standard error: 0.5985 on 373 degrees of freedom
## Multiple R-squared:  0.1226, Adjusted R-squared:  0.1062 
## F-statistic: 7.449 on 7 and 373 DF,  p-value: 0.00000002143

Explicit comparison order effects

## # weights:  27 (16 variable)
## initial  value 418.571282 
## iter  10 value 247.873414
## iter  20 value 245.154477
## iter  30 value 245.036208
## final  value 245.035637 
## converged
## Call:
## multinom(formula = dv_comp ~ population * boarding * cb_dvorder, 
##     data = data)
## 
## Coefficients:
##          (Intercept) populationoccluded boardingskewed cb_dvordersample_pop
## the same    3.610184          -1.242676     -2.3737962           -0.7200521
## taller      1.790456          -1.096115     -0.6205841           -1.3845531
##          populationoccluded:boardingskewed
## the same                          1.441669
## taller                            1.024843
##          populationoccluded:cb_dvordersample_pop
## the same                                12.43378
## taller                                  11.36994
##          boardingskewed:cb_dvordersample_pop
## the same                            2.192665
## taller                              3.306657
##          populationoccluded:boardingskewed:cb_dvordersample_pop
## the same                                             -0.4801181
## taller                                                0.1574901
## 
## Std. Errors:
##          (Intercept) populationoccluded boardingskewed cb_dvordersample_pop
## the same    1.013025           1.179388       1.081463             1.246554
## taller      1.079789           1.290726       1.145210             1.413848
##          populationoccluded:boardingskewed
## the same                          1.334891
## taller                            1.441608
##          populationoccluded:cb_dvordersample_pop
## the same                                130.2371
## taller                                  130.2403
##          boardingskewed:cb_dvordersample_pop
## the same                            1.662764
## taller                              1.786296
##          populationoccluded:boardingskewed:cb_dvordersample_pop
## the same                                               24.92392
## taller                                                 24.92074
## 
## Residual Deviance: 490.0713 
## AIC: 522.0713
## Analysis of Deviance Table (Type II tests)
## 
## Response: dv_comp
##                                LR Chisq Df            Pr(>Chisq)    
## population                        2.456  2              0.292913    
## boarding                         69.809  2 0.0000000000000006938 ***
## cb_dvorder                        9.985  2              0.006787 ** 
## population:boarding               1.241  2              0.537708    
## population:cb_dvorder             7.498  2              0.023543 *  
## boarding:cb_dvorder               7.726  2              0.021003 *  
## population:boarding:cb_dvorder    0.248  2              0.883589    
## ---
## Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1

Session info

## R version 4.4.2 (2024-10-31)
## Platform: aarch64-apple-darwin20
## Running under: macOS Sequoia 15.6
## 
## Matrix products: default
## BLAS:   /Library/Frameworks/R.framework/Versions/4.4-arm64/Resources/lib/libRblas.0.dylib 
## LAPACK: /Library/Frameworks/R.framework/Versions/4.4-arm64/Resources/lib/libRlapack.dylib;  LAPACK version 3.12.0
## 
## locale:
## [1] en_US.UTF-8/en_US.UTF-8/en_US.UTF-8/C/en_US.UTF-8/en_US.UTF-8
## 
## time zone: America/New_York
## tzcode source: internal
## 
## attached base packages:
## [1] stats     graphics  grDevices utils     datasets  methods   base     
## 
## other attached packages:
##  [1] effectsize_1.0.0 emmeans_1.10.4   nnet_7.3-19      lmerTest_3.1-3  
##  [5] lme4_1.1-35.5    Matrix_1.7-1     car_3.1-3        carData_3.0-5   
##  [9] ggtext_0.1.2     lubridate_1.9.3  forcats_1.0.0    stringr_1.5.1   
## [13] dplyr_1.1.4      purrr_1.0.2      readr_2.1.5      tidyr_1.3.1     
## [17] tibble_3.2.1     ggplot2_3.5.1    tidyverse_2.0.0  gt_0.11.1       
## [21] scales_1.3.0     janitor_2.2.0    here_1.0.1      
## 
## loaded via a namespace (and not attached):
##  [1] gridExtra_2.3       sandwich_3.1-1      rlang_1.1.4        
##  [4] magrittr_2.0.3      multcomp_1.4-26     snakecase_0.11.1   
##  [7] compiler_4.4.2      systemfonts_1.1.0   vctrs_0.6.5        
## [10] pkgconfig_2.0.3     crayon_1.5.3        fastmap_1.2.0      
## [13] backports_1.5.0     labeling_0.4.3      rmarkdown_2.29     
## [16] markdown_1.13       tzdb_0.4.0          nloptr_2.1.1       
## [19] ragg_1.3.2          bit_4.5.0.1         xfun_0.49          
## [22] cachem_1.1.0        jsonlite_1.8.9      parallel_4.4.2     
## [25] cluster_2.1.6       R6_2.5.1            bslib_0.8.0        
## [28] stringi_1.8.4       boot_1.3-31         rpart_4.1.23       
## [31] jquerylib_0.1.4     numDeriv_2016.8-1.1 estimability_1.5.1 
## [34] Rcpp_1.0.13         knitr_1.49          zoo_1.8-12         
## [37] base64enc_0.1-3     parameters_0.24.0   splines_4.4.2      
## [40] timechange_0.3.0    tidyselect_1.2.1    rstudioapi_0.17.1  
## [43] abind_1.4-8         yaml_2.3.10         codetools_0.2-20   
## [46] lattice_0.22-6      withr_3.0.2         bayestestR_0.15.0  
## [49] coda_0.19-4.1       evaluate_1.0.1      foreign_0.8-87     
## [52] survival_3.7-0      xml2_1.3.6          pillar_1.10.0      
## [55] checkmate_2.3.2     insight_1.0.0       generics_0.1.3     
## [58] vroom_1.6.5         rprojroot_2.0.4     hms_1.1.3          
## [61] commonmark_1.9.2    munsell_0.5.1       minqa_1.2.8        
## [64] glue_1.8.0          Hmisc_5.1-3         tools_4.4.2        
## [67] data.table_1.15.4   mvtnorm_1.3-1       grid_4.4.2         
## [70] datawizard_0.13.0   colorspace_2.1-1    nlme_3.1-166       
## [73] htmlTable_2.4.3     Formula_1.2-5       cli_3.6.3          
## [76] textshaping_0.4.0   ggthemes_5.1.0      gtable_0.3.5       
## [79] sass_0.4.9          digest_0.6.37       TH.data_1.1-2      
## [82] htmlwidgets_1.6.4   farver_2.1.2        htmltools_0.5.8.1  
## [85] lifecycle_1.0.4     gridtext_0.1.5      bit64_4.5.2        
## [88] MASS_7.3-61