The things I messed up

When you write 1000 pages of stuff, invariably you mess some things up. Imperfections should be embraced, so here is a list of mine for you to embrace or get annoyed at me about. Hopefully the former.

Chapter 9

I had a massive brain fart with the Smart Alex questions in this chapter. Although I adapted the tasks from the IBM SPSS version of this book, for some tasks this adapted text didn’t find its way into the final manuscript. What Can I say, it was an intense time.

  • Alex Task 3: the data files is called self_help.csv not penis.csv.
  • Alex Task 4: The example should refer to this book not Field & Hole. It should read:

“… They ran their own experiment (N = 500) in which relationship happiness was measured after participants had read their book and after reading one of mine (Field, 2026). (Participants read the books in counterbalanced order with a six month delay.) Was relationship happiness greater after reading their wonderful contribution to pop psychology than after reading my tedious tome?” Similarly the data are stored in self_help_dsur.csv not field_hole.csv).

  • Alex task 5: The stuff in parenthesis should be ignored: “Plot an error bar graph of the data in Task 1 (remember to adjust for the fact that the data are from a repeated-measures design.)
  • Alex Task 6 should read:

Repeat the t-test from Task 5 but turn of Welch’s correction. Then fit a linear model to the data in Task 5 to see whether life satisfaction is significantly predicted from the type of animal. What do you notice about the t-value and significance in this model compared to Task 5?

  • Alex Task 8 should read:

A psychologist was interested in the cross-species differences between men and dogs. She observed a group of dogs and a group of men in a naturalistic setting (20 of each). She classified several behaviours as being dog-like (urinating against trees and lampposts, attempts to copulate with anything that moved, and attempts to lick their own genitals). For each man and dog she counted the number of dog-like behaviours displayed in a 24-hour period. It was hypothesized that dogs would display more dog-like behaviours than men. Test this hypothesis using a robust test. (men_dogs.csv)

  • Alex Task 9 should read:

Both Ozzy Osbourne and Judas Priest have been accused of putting backward masked messages on their albums that subliminally influence poor unsuspecting teenagers into doing things like blowing their heads off with shotguns. A psychologist was interested in whether backward masked messages could have an effect. He created a version of Taylor Swifts’ ‘Shake it off’ that contained the masked message ‘deliver your soul to the dark lord’ repeated in the chorus. He took this version, and the original, and played one version (randomly) to a group of 32 people. Six months later he played them whatever version they hadn’t heard the time before. So, each person heard both the original and the version with the masked message, but at different points in time. The psychologist measured the number of satanic intrusions the person had in the week after listening to each version. Test the hypothesis that the backward message would lead to more intrusions (dark_lord.csv) using a robust test.

  • Alex Task 10 should read: “Thinking back to Labcoat Leni’s Real Research 4.1, test whether the number of offers was significantly different in people listening to Bon Scott than in those listening to Brian Johnson (acdc.csv) using a robust independent t-test with bootstrapping. Do your results differ from Oxoby (2008)?”

Chapter 10

  • Alex Task 9 should be labelled as 8.

Chapter 12

  • P. 694: Code for Figure 12.7. The labs() function does not need the colour and fill arguments: labs(x = "Pre-treatment happiness (0-10)", y = "Post-treatment happiness (0-10)")

Chapter 16

  • Alex Task 6 should read:

My wife believes that she has received fewer friend requests from random men on Facebook since she changed her profile picture to a photo of us both. Imagine we took 40 women who had profiles on a social networking website; 17 of them had a relationship status of ‘single’ and the remaining 23 had their status as ‘in a relationship’ (rel_status). We asked these women to set their profile picture (profile_pic) to a photo of them on their own (alone) and to count how many friend request they got from men over 3 weeks, then to switch it to a photo of them with a man (couple) and record their friend requests from random men over 3 weeks. Fit a model to see if friend requests are affected by relationship status and type of profile picture (profile_pic.csv).

  • Alex Task 7 should read:

Labcoat Leni’s Real Research 5.2 described a study in which researchers reasoned that if red was a proxy signal to indicate sexual proceptivity then men should find red female genitalia more attractive than other colours (Johns et al., 2012). They also recorded the men’s sexual experience (partners) as ‘some’ or ‘very little’. Fit a model to test whether attractiveness was affected by genitalia colour (pale pink, light pink, darkpink, red) and sexual experience (johns_2012.csv). Look at page 3 of Johns et al. to see how to report the results.

Chapter 17

  • p. 948: Output 17.5 and “Output 17.5 shows that the root mean square of the residuals (RMSR but labelled RMSA in the output) …”. Since publication, the easystats crew have amended the labelling in their output so that RMSR is correctly labelled as RMSR.
  • p. 975, Figure 17.15: There are two item 22s and no item 24. The second item 22 should be item 23 and the existing item 23 should be item 24.

Chapter 18

  • p. 1018: It would be helpful if I mentioned that the ggmosaic package needs to be installed from github using devtools::install_github("haleyjeppson/ggmosaic")

Chapter 19

  • Alex Task 12 was supposed to be deleted because I ended up not covering multinomial logistic regression.

References

Johns, S. E., Hargrave, L. A., & Newton-Fisher, N. E. (2012). Red is not a proxy signal for female genitalia in humans. PLoS One, 7, e34669. https://doi.org/https://doi.org/10.1371/journal.pone.0034669