1. OpenRepGrid
An R package for the analysis of repertory grids
EPCA Conference, Dublin, June 30, 2012
Mark Heckmann
University of Bremen, Germany

2. PART I
• Motivation for OpenRepGrid
• Why R?
• The OpenRepGrid project
PART II
• Gettings started with R
• Gettings started with OpenRepGrid
• Basic grid analysis
PART III
• Creating a report
• Adding functionality

3. Part I

6. Clinicians
Researchers
Business
consultant
User diversity leads to Coaches
different user needs …

7. General requirements for (grid) software
• Durability
• Availability
• Functionality
• Compatibility
• Documentation
• Openness
• Extensibility
• Usability

8. Current
situa+on

9. No grid software
offers all methods
of analysis that
have been
devised in the
literature
Source: http://callcentersindia.files.wordpress.com/2010/06/selection-process.png

10. Journal of Constru ctivist Psychology, 13:1–26, 2000
Copyright ã 2000 Taylor & Francis
1072-0537/00 $12.00 + .00
THE STRUCTURAL QUADRANTS METHOD:
A NEW APPROACH TO THE ASSESSMENT OF CONSTRUCT
SYSTEM COMPLEXITY VIA THE REPERTORY GRID
JOSEP GALLIFA and LUIS BOTELLA
Department of Psychology, Ramon Llull Un iversity, Barcelona, Spain
This article presents a new mathematical m ethod (the Structu ral Quadrants M ethod)
for the assessm ent of constru ct system complexity via the repertory grid. The Struc-
tural Q uadrants M ethod (SQ M ) is presented step by step, and its sensitivity to
grid structu re is illustrated by applying it to five case studies. A validational study
demonstrating the discrim inative power of the SQ M and comparing it to tradi-
tional measures is included. Results indicate that the SQ M discrim inates between a
group of 11 experts and one of 11 novices in term s of grid com plexity as expected
(i.e., detecting high degrees of differentiation and integration in the experts’ grids
and low degrees of differentiation and integration in the novices’ grids). The dis-
crim inative power of the SQ M is unparalleled by the traditional measures of grid
structu re compared in this article. The article ends with a section on the distinctive
advantages of the S QM and som e suggest ions for future research.

11. No framework to
support
experimental
types of analysis
Not extensible
by user

12. The output of
most programs
does not easily
lend itself to
subsequent
computation
Source: http://www.jacksofscience.com/wp-content/uploads/2008/05/computing_occurs.jpg

13. Development by a
single person or a small
group of researchers,
each with their own
special competencies
in a certain field of
research and often
limited time resources.
(Fromm, 2009)

14. No joint
community effort
to improve a
program:
Development and
documentation is
delegated to the
software providers
Source: http://www.kirchen-und-kapellen.de/images/content/Community.jpg

15. “the programs that are currently available have a
short shelf-life in that they are unlikely to be
updated once their creators have retired”
(Fransella, Bannister & Bell, 2004, p. 38)
Discontinued
development
once its initiators
have moved on to
other fields or
retired
Source:
h1p://evolu+on.berkeley.edu/evosite/misconceps/images/misconcep+ons_beavers2.gif

16. What to do?
• Software design that enables users to
contribute to its development
• Set up infra- and communication
structures to foster participation in a
joint development
Go
Open
Source!

17. Why ?

18. • Because I am familiar with it 
• is the lingua franca in the field of
statistics
• runs on all major platforms
• is managable by non-programmers
• becomes increasingly popular within
the social sciences

19. Muenchen, R. A. (2012). Popularity of data analysis software.
http://r4stats.com/articles/popularity/

20. • provides an underlying framework for
further computations
• provides a wealth of functionality

21. Muenchen, R. A. (2012). Popularity of data analysis software.
http://r4stats.com/articles/popularity/

22. • provides an underlying framework for
further computations
• provides a wealth of functionality
• fosters extensibility (GUI, 3D etc.)
Suitable for Open Source
grid software development

23. OpenRepGrid project
OpenRepGrid R package OpenRepGrid Wiki

24. User entry points
• Give feedback: bug reports,
suggestions ...
• Supply method descriptions to trigger
development
• Provide R code snippets
• Generate tutorials and case studies
• Join the R package development team

25. Development phases
Phase
1
Phase
2
• Create wide range of • Adding graphical user
analysis methods
interface
• Development of Wiki
• Target: Researchers
• Target: Practicioners
and casual users

26. Part II

27. Setup
+
www.r-project.org www.rstudio.org

28. 28

29. Basics
• R is interactive
• Navigate through former commands by
pressing up and down arrows
• Everything after a hash (#) is a comment
• Execute a command by pressing the enter-
key
29

30. Using R as a calculator
4 + 4 ! ! !
! !# Addition!
4 - 1 ! !
! !# Subtraction!
4 / 2 ! ! !
! !# Division!
2 * 2 ! ! !
! !# Multiplication!
2^2 ! ! ! !# Power!
!
2 + 2 * 3! ! !# standard calculating rules !
2 * 2^3 !
! ! ! !!
(2-1) * (2+2) ! !# standard use of brackets!
30

31. Variable assignments
!
a <- 2 + 2 ! !# assignment operator!
!
a ! ! ! ! !# variable value is 4!
!
a <- 100 ! ! # change variable value!
a * 10 ! ! ! ! !# use the variable !
!
a <- ”Some text" !# assign text to variable!
a * 10 ! ! !# error!
31

32. Objects
Objects (Variables) names may contain numbers,
letters, underscores or dots. The name must not
contain a function (+, - *, / etc.).
object1 <- 10!
object.1 <- hallo !
!
Names are case sensitive
myObject <- 1!
myobject <- 2
32

33. Functions
Function (lat. performance, execution)
Every function uses round brackets
c()
!
a <- c(3,4,5)!
!
!
rnorm()!
rnorm(4)!
!
!
33

34. Functions
Commands inside the function’s round brackets are
called arguments. A function may take zero to many
arguments.
rnorm(3) !
[1] -0.3628728 -0.4580532 -1.3729865!
!
Every function has a documented set of arguments
!
?rnorm!
!
34

35. Nurse, get on the internet, go to SURGERY.COM,
scroll down and click on the , Are you totally lost? icon.
35

36. R Help System
36

37. Some functions
a <- c(1.2, 3.3, 6.5)!
round(a) ! !!
sum(a) ! ! !
mean(a) !
! !
!
37

38. Extracting vector elements
a[1]! ! ! ! ! !# retrieve first element!
!
a[c(1,2)]! ! ! !# elements 1 and 2!
!
!
# Delete elements!
a[-1] ! ! ! !# delete first element!
!
!
a <- a[-1]!
38

39. Matrices
?matrix!
m <- matrix(1:9, ncol=3)!
!
m[rows , columns]!
!
m[1 , ] ! ! !# first row, all columns!
m[ , 1] ! ! !# frist column, all rows!
m[1:2, 1]! ! !# first two rows, all columns!
!
m[-1, ] ! ! !# delete first row!
!
!
39

40. Replace matrix elements
m[1, 1] <- 999!
m!
!
!
m[1 , ] <- c(90,91,92)!
m!
!!
40

41. Exploring software
features on
www.openrepgrid.org

42. Web Repository with
3.500+ packages
OpenRepGrid
Load package
when starting R

45. Part III

46. Task
Create a function that
counts the number of
midpoint ratings

47. Logical operators
TRUE!
FALSE!
!
2 == 1 ! ! ! ! !# equal?!
c(1,2,1,3) == 1
!!
47

48. Writing new functions
f <- function(){!
!# some R commands!
}!
f()!
!
!
f <- function(x){!
!x!
}!
f(12)!
!
!

49. Writing new functions
f <- function(x){!
!sum(x) / length(x)!
}!
!
a <- c(1,2,3,4) !
f(a)!
!
!

50. !
midpoints <- function(x) { !
!scores <- getRatingLayer(x) !
!mid <- getScaleMidpoint(x) !
!sum(scores == mid)!
}!
!
midpoints(bell2010)!

51. Task
Calculate the Slater distance for
all grids bewteen the elements
„A party I would vote for“ and
„The Green Party (Grüne)“

52. slater <- lapply(x, distanceSlater, out=F)!
sapply(slater , function(x) x[1,6])!

53. markheckmann.github.com/
OpenRepGrid/

54. Writing a
report

55. out now!

56. Creating reports for OpenRepGrid
RStudio
+

57. Using R markdown
• Markdown is a lightweight language to
structure a document
• R code chunks can be directly included
• Include R code between the following
tags
```{r}
# Some R Code here
```

58. Press
to
generate
document
Insert
tags

60. Want to participate?
You have suggestions or ideas?
Just get in touch!

61. Literature
• Fransella, F., Bell, R. C., & Bannister, D. (2004). A manual for repertory
grid technique (2nd ed.). Chichester: John Wiley & Sons.
• Fromm, M. (2009). Grid Software. European Personal Construct
Association. Retrieved July 25, 2010, from http://www.epca-net.org/
repgrid/software
• Heckmann, M. (2011). OpenRepGrid - An R package for the analysis
of repertory grids (Unpublished diploma thesis). University of Bremen,
Bremen, Germany.
• Muenchen, R. A. (2011). The Popularity of Data Analysis Software.
Retrieved March 28, 2011, from http://sites.google.com/site/
r4statistics/popularity
• R Development Core Team. (2011). R: A language and environment
for statistical computing. Vienna, Austria: R Foundation for Statistical
Computing. ISBN 3-900051-07-0, URL http://www.R-project.org/.