Statistical Exploratory Analysis with “EnQuireR”

1. Introduction2. Installation3. How to4. Report

Statistical exploratory analysis with EnQuireR

Descriptive analysis & Exploratory analysis 1. Introduction

1. Descriptive statistic are mostly “Univariate analysis”. It involves the examination across cases of a single variable, focusing on three characteristics: the distribution; the

central tendency; and the dispersion

Example: a frequency distribution chart

2. Exploratory analysis is an approach to analyzing data for the purpose of formulating hypotheses. “Multivariate or Factor analysis” are used to uncover the latent structure (dimensions) of a set of variables. It reduces attribute space from a larger number of variables to a smaller number of factors and allows the definition of

statistically consistent cluster.

Example: Multivariate cluster analysis from three measurements of femur properties

source

From Wikipedia

Statistical exploratory analysis with EnQuireR

EnQuireR: a dedicated package in the R environment

1. Introduction

1. “R” is a free software environment for statistical computing and graphics. (http://www.r-project.org ) – It is the Open Source Equivalent of SPSS, SAS or STATA – Mostly used in University – Free support over various forums.

2. EnQuireR is a “R” package that allows the statistical exploration of data issued from questionnaires (http://enquirer.free.fr/EnQuireR.pdf; http://cran.r-project.org/web/packages/EnQuireR/EnQuireR.pdf)

Multiple Correspondence Analysis (MCA) : A type of multivariate analysis that allows to

“Summarize the pattern of relationships between different categorical variables”

Statistical exploratory analysis with EnQuireR

A few download (all Free & Open source)

1. http://lib.stat.cmu.edu/R/CRAN/bin/windows/base/ (direct download) =>The R environment

2. http://www.texniccenter.org/resources/downloads/29 (direct download) => Used to generate PDF

3. http://miktex.org/2.9/setup (direct download) => Used to generate PDF

4. http://enquirer.free.fr/ (direct download) => The specific R package for questionnaire analysis

Install the first 3 applications!

2. Installation

Statistical exploratory analysis with EnQuireR

Installation

If you are behind a proxy, add “–internet2” to your exe shortcut

“R” will then use the same proxy as your local Internet Explorer

2. Installation

Statistical exploratory analysis with EnQuireR

Setting up a “Working Directory”

Start from your customized shortcut

This is the “R shell”

Change the working directory with “setwd()” (here D:/stat)

To check your working directory, enter: getwd()

3. How to

Statistical exploratory analysis with EnQuireR

Install the local package “EnquireR”3. How to

Statistical exploratory analysis with EnQuireR

Load the library to start R Commander

Enter library(“EnQuireR”) in

the R shell

This will open a new window for

the “R Commander”

console

3. How to

Statistical exploratory analysis with EnQuireR

Load your dataset

1. In R commander, import a new dataset

2. Enter your-dataset-name

3. Select the excel file in your file system.

4. Select your worksheet in the excel document

3. How to

Statistical exploratory analysis with EnQuireR

Start the analysis

Your data has been loaded.Note that column name may

have been automatically renamed

1. Enter: “res.enmca <- ENMCA(your-dataset-name, report=TRUE) “

2. Click “Submit”

3. Wait… this a lot of computation !!!

4. A directory named "EnQuireR" has been created in your working directory with all your reports

3. How to

Statistical exploratory analysis with EnQuireR

Get your reports

The EnQuireR package provides two kinds of automatically generated reports:

1. A synthetic report made of slides and divided in 2 parts: Multivariate exploration of the questionnaire Typology of the individuals.

2. A detailed and exhaustive report: Indicates whether a given set of categorical variables

depends on another one. Definition of the axis of the correspondence map Spreading of individuals and categories in the

correspondence map. List of categories that best describe each automatically

defined cluster

4. Report

Statistical exploratory analysis with EnQuireR

Requirement on data

• Data should be “categorical” (i.e. non continuous), typically closed response questions

• Categories should have more than one level

• Data should not contain space – to be replaced by point for instance

• Column names should be as short as possible to be better visualized in the final report

4. Report

Statistical exploratory analysis with EnQuireR

Usage for UNHCR

Analysis could be performed on:• Registration data (proGres)• IDP profiling• Site assessment (needs assessment)

Possibility to define the characteristics of statistically homogenous groups.

Those characteristics can then be used to build targeted assistance programme!

4. Report

Examples of case studies can be found here: http://enquirer.free.fr/case-studies/