For this exercise, please try to reproduce the results from Study 1 of the associated paper (Joel, Teper, & MacDonald, 2014). The PDF of the paper is included in the same folder as this Rmd file.

Methods summary:

In study 1, 150 introductory psychology students were randomly assigned to a “real” or a “hypothetical” condition. In the real condition, participants believed that they would have a real opportuniy to connect with potential romantic partners. In the hypothetical condition, participants simply imagined that they are on a date. All participants were required to select their favorite profile and answer whether they were willing to exchange contact information.

Target outcomes:

Below is the specific result you will attempt to reproduce (quoted directly from the results section of Study 1):

We next tested our primary hypothesis that participants would be more reluctant to reject the unattractive date when they believed the situation to be real rather than hypothetical. Only 10 of the 61 participants in the hypothetical condition chose to exchange contact information with the unattractive potential date (16%). In contrast, 26 of the 71 participants in the real condition chose to exchange contact information (37%). A chi-square test of independence indicated that participants were significantly less likely to reject the unattractive potential date in the real condition compared with the hypothetical condition, X^2(1, N = 132) = 6.77, p = .009.

Step 1: Load packages

library(tidyverse) # for data munging
library(knitr) # for kable table formating
library(haven) # import and export 'SPSS', 'Stata' and 'SAS' Files
library(readxl) # import excel files

# #optional packages:
# library(broom)
# library(labelled)# converts SPSS's labelled to R's factor

Step 2: Load data

# Just Study 1
d <- read_sav('data/Empathy Gap Study 1 data.sav')

Step 3: Tidy data

real_cond <- d |> 
  filter(condition == 1)

hypo_cond <- d |> 
  filter(condition == 0)

Step 4: Run analysis

Descriptive statistics

Only 10 of the 61 participants in the hypothetical condition chose to exchange contact information with the unattractive potential date (16%). In contrast, 26 of the 71 participants in the real condition chose to exchange contact information (37%).

# reproduce the above results here
hypo_exchange_table <- hypo_cond |> 
  select(exchangeinfo) |> 
  table()

cat("Only ", hypo_exchange_table[1], " of the ", sum(hypo_exchange_table)," participants in the hypothetical condition chose to exchange contact information with the unattractive potential date (", round(100*hypo_exchange_table[1]/sum(hypo_exchange_table)), "%).", sep = "")
## Only 10 of the 61 participants in the hypothetical condition chose to exchange contact information with the unattractive potential date (16%).
real_exchange_table <- real_cond |> 
  select(exchangeinfo) |> 
  table()

cat(real_exchange_table[1], " of the ", sum(real_exchange_table)," participants in the real condition chose to exchange contact information with the unattractive potential date (", round(100*real_exchange_table[1]/sum(real_exchange_table)), "%).", sep = "")
## 26 of the 71 participants in the real condition chose to exchange contact information with the unattractive potential date (37%).

Inferential statistics

A chi-square test of independence indicated that participants were significantly less likely to reject the unattractive potential date in the real condition compared with the hypothetical condition, X^2(1, N = 132) = 6.77, p = .009.

Hint: if you are using the function chisq.test(), make sure to set the continuity correction to false (“correct = FALSE”) since sample size is greater than 20.

# reproduce the above results here

cont_table <- tibble(hypo = as_tibble(hypo_exchange_table)$n, real = as_tibble(real_exchange_table)$n)

cont_table
## # A tibble: 2 × 2
##    hypo  real
##   <int> <int>
## 1    10    26
## 2    51    45
test_res <- chisq.test(cont_table, correct = FALSE)
test_res
## 
##  Pearson's Chi-squared test
## 
## data:  cont_table
## X-squared = 6.7674, df = 1, p-value = 0.009284
cat("A chi-square test of independence indicated that participants were significantly less likely to reject the unattractive potential date in the real condition compared with the hypothetical condition, X^2(", test_res$parameter,", N = ", sum(cont_table),") = ", round(test_res$statistic, 2),", p = ", round(test_res$p.value, 3),".", sep = '')
## A chi-square test of independence indicated that participants were significantly less likely to reject the unattractive potential date in the real condition compared with the hypothetical condition, X^2(1, N = 132) = 6.77, p = 0.009.

Step 5: Reflection

Were you able to reproduce the results you attempted to reproduce? If not, what part(s) were you unable to reproduce?

Yes, I was fully able to reproduce the results I wanted to reproduce.

How difficult was it to reproduce your results?

It was fairly straightforward to reproduce the results. I didn’t get stuck anywhere. The data and the explanations in the paper, made it clear what I had to do.

What aspects made it difficult? What aspects made it easy?

It was helpful to have the results from the paper to compare to. That way, I could easily identify if I made a mistake. It data was also pre-cleaned to exclude invalid observations, which simplified the work I had to do for this assignment. One potential hang-up was the continuity correction in the chi-squared test, but the hint helped avoid it.