OpenRepGrid An R package for the analysis of repertory grids

EPCA Conference, Dublin, June 30, 2012

Mark Heckmann University of Bremen, Germany

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

Part I

User diversity leads to different user needs …

Clinicians

Business consultant

Researchers

Coaches

General requirements for (grid) software

•  Durability

•  Availability

•  Functionality

•  Compatibility

•  Documentation

•  Openness

•  Extensibility

•  Usability

Current    situa+on  

 

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

1

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 University, Barcelona, Spain

This article presents a new mathematical method (the Structural Quadrants Method)for the assessment of construct system complexity via the repertory grid. The Struc-tural Quadrants Method (SQM) is presented step by step, and its sensitivity togrid structure is illustrated by applying it to five case studies. A validational studydemonstrating the discriminative power of the SQM and comparing it to tradi-tional measures is included. Results indicate that the SQM discriminates between agroup of 11 experts and one of 11 novices in terms of grid complexity as expected(i.e., detecting high degrees of differentiation and integration in the experts’ gridsand low degrees of differentiation and integration in the novices’ grids). The dis-criminative power of the SQM is unparalleled by the traditional measures of gridstructure compared in this article. The article ends with a section on the distinctiveadvantages of the SQM and some suggest ions for future research.

The term cognitive complexity was initially introduced by Bieri (1955),and defined as “the capacity to construe social behavior in a multidi-mensional way” (Bieri et al., 1966, p. 185). As discussed by G. J. Neimeyer(1992, p. 94), such a definition of construct system complexity empha-sizes differentiation, understood as “the relative number of differentdimensions of judgment used by a person.” In line with this notion ofcomplexity as differentiation, traditional measures of construct systemcomplexity have relied on an attempt to assess the degree of overlapor redundancy in the use of constructs, with higher degrees of overlapreflecting lower levels of differentiation and complexity (G. J. Neimeyer,1992).

A theoretically coherent notion of construct system complexity can-not solely rely on the system’s level of differentiation but must also

Received 7 May 1997; accepted 24 July 1998.The authors would like to thank Robert A. Neimeyer and two anonymous review-

ers for their insightful comments on earlier drafts.Address correspondence to Luis Botella, Department of Psychology, Ramon Llull

University, Cister 24–34, 08022-Barce lona, Spain. E-mail: lluisbg@blanquerna.url.es

Journal of Constructivist Psychology, 13:1–26, 2000Copyright ã 2000 Taylor & Francis1072-0537/00 $12.00 + .00

Not extensible by user

No framework to support experimental types of analysis

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

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)

Source: http://www.kirchen-und-kapellen.de/images/content/Community.jpg

No joint community effort

to improve a program:

Development and documentation is delegated to the

software providers

Source:  h1p://evolu+on.berkeley.edu/evosite/misconceps/images/misconcep+ons_beavers2.gif  

Discontinued development

once its initiators have moved on to

other fields or retired

“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)

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!  

Why ?

•  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

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•  provides an underlying framework for

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•  provides a wealth of functionality

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•  provides an underlying framework for

further computations

•  provides a wealth of functionality

•  fosters extensibility (GUI, 3D etc.)

Suitable for Open Source grid software development

OpenRepGrid project

OpenRepGrid R package OpenRepGrid Wiki

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

Development phases

Phase  1  

• Create wide range of analysis methods  

• Development of Wiki

• Target: Researchers

Phase  2  

• Adding graphical user interface

• Target: Practicioners and casual users

Part II

Setup

+  www.r-project.org www.rstudio.org

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

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!

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!

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  

33  

Functions

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

rnorm()!rnorm(4)!!!

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!!

35  

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

36  

R Help System

37  

Some functions

a <- c(1.2, 3.3, 6.5)!round(a) ! !!sum(a) ! ! !mean(a)! ! !!

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]!

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!!

40  

Replace matrix elements

m[1, 1] <- 999!m!!!m[1 , ] <- c(90,91,92)!m!!!

Exploring software features on

www.openrepgrid.org

Web Repository with 3.500+ packages

OpenRepGrid

Load package when starting R

Part III

Create a function that counts the number of

midpoint ratings

Task

47  

Logical operators

TRUE!FALSE!!2 == 1 ! ! ! ! !# equal?!c(1,2,1,3) == 1!!

Writing new functions

f <- function(){!!# some R commands!

}!f()!!!f <- function(x){!!x!

}!f(12)!! !

Writing new functions

f <- function(x){!!sum(x) / length(x)!

}!!a <- c(1,2,3,4) !f(a)!! !

!midpoints <- function(x) { !!scores <- getRatingLayer(x) !!mid <- getScaleMidpoint(x) !!sum(scores == mid)!

}!!midpoints(bell2010)!

Calculate the Slater distance for all grids bewteen the elements

„A party I would vote for“ and

„The Green Party (Grüne)“

Task

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

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Writing a report

out now!

Creating reports for OpenRepGrid

+  RStudio

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 ```

Press  to  generate    document  

Insert  tags  

Want to participate?

You have suggestions or ideas?

Just get in touch!

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/.