analysis_qualtrics.R

msbernst — Sep 16, 2014, 9:39 AM

library(aod)

Warning: package 'aod' was built under R version 3.0.2

library(ggplot2)
library(plyr)

setwd('~/Documents/projects/darkmatter/analysis/qualtrics/')

musicdata <- read.csv("qualtrics_pilot.csv")

count(musicdata, c('is_hegemonic'))

  is_hegemonic freq
1            0    2
2            1   63

qplot(is_hegemonic, data = musicdata, geom="histogram")

stat_bin: binwidth defaulted to range/30. Use 'binwidth = x' to adjust
this.

plot of chunk unnamed-chunk-1


posted_ot_plot <- ggplot(musicdata, aes(x = posted_on_topic)) + geom_histogram()
posted_ot_plot + facet_grid(is_hegemonic ~ condition)

stat_bin: binwidth defaulted to range/30. Use 'binwidth = x' to adjust
this. stat_bin: binwidth defaulted to range/30. Use 'binwidth = x' to
adjust this. stat_bin: binwidth defaulted to range/30. Use 'binwidth = x'
to adjust this.

plot of chunk unnamed-chunk-1

count(musicdata, c('is_hegemonic', 'condition', 'posted_on_topic'))

  is_hegemonic condition posted_on_topic freq
1            0      over               1    2
2            1      over               0   32
3            1      over               1    2
4            1     under               0   27
5            1     under               1    2


print(summary(musicdata))

  is_hegemonic   condition      posted      posted_on_topic 
 Min.   :0.000   over :36   Min.   :0.000   Min.   :0.0000  
 1st Qu.:1.000   under:29   1st Qu.:0.000   1st Qu.:0.0000  
 Median :1.000              Median :0.000   Median :0.0000  
 Mean   :0.969              Mean   :0.215   Mean   :0.0923  
 3rd Qu.:1.000              3rd Qu.:0.000   3rd Qu.:0.0000  
 Max.   :1.000              Max.   :1.000   Max.   :1.0000

musicdata$condition <- factor(musicdata$condition)
logit <- glm(posted_on_topic ~ is_hegemonic + condition, data = musicdata, family = "binomial")
print(summary(logit))


Call:
glm(formula = posted_on_topic ~ is_hegemonic + condition, family = "binomial", 
    data = musicdata)

Deviance Residuals: 
   Min      1Q  Median      3Q     Max  
-0.378  -0.378  -0.348  -0.348   2.380  

Coefficients:
               Estimate Std. Error z value Pr(>|z|)
(Intercept)       17.57    2797.44    0.01     0.99
is_hegemonic     -20.34    2797.44   -0.01     0.99
conditionunder     0.17       1.03    0.16     0.87

(Dispersion parameter for binomial family taken to be 1)

    Null deviance: 40.020  on 64  degrees of freedom
Residual deviance: 29.768  on 62  degrees of freedom
AIC: 35.77

Number of Fisher Scoring iterations: 16

print(confint.default(logit))

                   2.5 %   97.5 %
(Intercept)    -5465.319 5500.452
is_hegemonic   -5503.224 5462.547
conditionunder    -1.856    2.196


# based on http://www.ats.ucla.edu/stat/r/dae/logit.htm