openintro (version 2.4.0)

mail_me: Influence of a Good Mood on Helpfulness

Description

This study investigated whether finding a coin influenced a person's likelihood of mailing a sealed but addressed letter that appeared to have been accidentally left in a conspicuous place. Several variables were collected during the experiment, including two randomized variables of whether there was a coin to be found and whether the letter already had a stamp on it.

Usage

mail_me

Format

A data frame with 42 observations on the following 4 variables.

stamped

a factor with levels no yes

found_coin

a factor with levels coin no_coin

gender

a factor with levels female male

mailed_letter

a factor with levels no yes

Details

The precise context was in a phone booth (this study is from the 1970s!), where a person who entered a phone booth would find a dime in the phone tray, which would be sufficient to pay for their phone call. There was also a letter next to the phone, which sometimes had a stamp on it.

Examples

table(mail_me)
(x <- table(mail_me[, c("mailed_letter", "found_coin")]))
chisq.test(x)

(x <- table(mail_me[, c("mailed_letter", "stamped")]))
chisq.test(x)

m <- glm(mailed_letter ~ stamped + found_coin + gender,
  data = mail_me,
  family = binomial
)
summary(m)