R: Publications of PhD Candidates

PhdPubs {vcdExtra} | R Documentation

## Publications of PhD Candidates

### Description

A data set giving the number of publications by doctoral candidates in biochemistry in relation to various predictors, originally from Long (1997).

There is a large number of zero counts. Is there evidence for a separate group of non-publishers?

### Usage

    data(PhdPubs)

### Format

A data frame with 915 observations on the following 6 variables.

`articles`

  number of articles published in the final three years of PhD studies

`female`

  dummy variable for gender, coded `1` for female

`married`

  dummy variable for marital status, coded `1` for married

`kid5`

  number of young children, age 5 and under

`phdprestige`

  prestige of the PhD department

`mentor`

  number of publications by the mentor in the preceeding three years

### Source

Long, J. S. (1997) Regression Models for Categorical and Limited Dependent Variables, Sage.

### Examples

    data(PhdPubs)
    # very uninformative
    hist(PhdPubs$articles, breaks=0:19, col="pink", xlim=c(0,20),
         xlab="Number of Articles")

    library(vcd)
    rootogram(goodfit(PhdPubs$articles), xlab="Number of Articles")
    # compare with negative binomial
    rootogram(goodfit(PhdPubs$articles, type="nbinomial"),
    	xlab="Number of Articles", main="Negative binomial")

[Package vcdExtra version 0.7-1 Index]