OVERVIEW

Contents

GenStat Discovery Edition
ICRAF – World Forestry Centre
ILRI
Massey University
University of KwaZulu-Natal
University of Reading (SSC)

GenStat Discovery Edition

The companion GenStat Discovery CD contains a free copy of a special version of GenStat that is available free to African users. GenStat was originally designed and developed at Rothamsted Experimental Station, Harpenden, UK and its design has been greatly been influenced by the application of statistics to agricultural research. It is especially strong in the analysis of designed experiments.

GenStat has been chosen as the primary software (along with Instat) for use with the Biometrics and Research Methods Teaching Resource because of its particular relevance to agriculture, for its comparative user friendliness, for the simplicity and elegance in the way that much of the statistical output is presented, for the way it encourages good statistical practice, and for its wide availability in Africa. VSN International, Hemel Hempstead, UK is now responsible for management of the software, its support and continued development.

The GenStat Discovery Edition is distributed in Africa by The ICRAF-ILRI Research Methods Group in Nairobi. Instructions are contained in the GenStat Discovery companion CD for its installation. New users of the Biometrics and Research Methods Teaching Resource will first need to download GenStat onto hard disc.

ICRAF - World Forestry Centre

Contents

1. GenStat Manual
2. Research Design
3. Research Data Management
4. Analysis and Interpretations

These training materials produced by ICRAF (research design, research data management and data analysis) focus on agroforestry research. Teachers, students or researchers of this or similar disciplines may find this material relevant.

ICRAF, together with Statistical Services Centre (SSC) Reading, have also developed a GenStat Manual to help researchers who wish to use GenStat for the analysis of their research data.

1. GenStat Manual

The primary purpose in writing this GenStat manual was to provide supporting materials for scientists on training courses in statistics. Whilst the case studies in the Biometrics and Research Methods Teaching Resource provide illustrations on the use of GenStat and its commands, teachers of students new to GenStat will find this GenStat manual valuable. Researchers or students requiring additional information on the application of GenStat to agricultural research will also find this useful. It contains various examples taken from the book ‘Statistical Methods in Agriculture and Experimental Biology’ by Mead, Curnow and Hasted and from course material developed by ICRAF and the University of Reading.

2. Research Design

This category contains materials on the design of agroforestry experiments, materials on surveys and participatory experiments and on-farm trials.

Summary

Lecture Notes

Session 1

Introduction

Session 2

Setting objectives

Session 3

Choosing treatments

Session 4

Site selection

Session 5

Replication

Session 6

Plot structure

Session 7

Randomization

Session 8

Sampling

Session 9

Assessments

Session 10

Plot layout

Session 11

Incomplete block designs

Session 12

Split-plot designs

Session 13

The experimental planning process

Session 14

An experimental design project

The category also covers preparing protocols, monitoring on-farm trials, collecting data on labour use in on-farm trials and assessing risk in on-farm trials. ‘On-farm Experiments’ zip

3. Research Data Management

This category provides various resources on data management. Special attention is paid to data backups and archiving. Finally, some specialised data management tools developed by ICRAF are introduced.

This manual Data management covers the importance of data management, designing a spreadsheet for data management, spreadsheet data entry, improving data querying efficiency, data modelling and building a data management strategy.

This section stresses how valuable one’s data are and how there is a high risk that sooner or later one’s computer will crash or will fail forever. The only way to avoid a loss of resources is to make backups on a regular basis in an organised way. It includes a technical note ‘A strategy against data disasters’ that serves as background and reference material for the research data management course.

4. Analysis and Interpretations

Materials under this category present a course on the analysis of data from agroforestry experiments, but, although the examples are from agroforestry, both the statistical and teaching ideas can be applied to trials from other agricultural application areas. Only one out of 17 sessions is dedicated to peculiarities of agroforestry research, and it should be easy to substitute other examples when using the materials. The materials were produced through a long-term collaboration between ICRAF and SSC (Reading).

The materials are presented in four parts.

ILRI

Basic Biometric Techniques in Experimental Design and Analysis

The Biometrics Unit of ILRI, Nairobi prepared course notes for an introductory course on basic biometry techniques for animal researchers (Biometrics Unit, ILRI, 2005). Teachers or researchers with elementary knowledge of statistics may find these course notes useful. The course contains data sets:

Massey University

Doug Stirling, a senior lecturer in the Institute of Information Sciences and Technology at Massey University in Palmerston North, New Zealand, has developed CAST (Computer Assisted Statistical Teaching). CAST is an electronic interactive textbook for teaching introductory statistics. It contains interactive diagrams to teach introductory statistical concepts. CAST makes extensive use of interactive diagrams to help explain the statistical concepts. The interactive diagrams make the ideas more memorable and help to retain interest.

The public version of CAST can be accessed from http://cast.massey.ac.nz but the publishers of CAST developed a customised version for Africa and it is contained in this CD-ROM. To access CAST in this CD-ROM click CAST. After you login a page appears in which you can select one of the two modules of the African version of CAST or one of the three modules of the Climatic version. (Note that only the first of each has been fully customised at present. The others only give some feel for the possible contents of these modules.). The customised version for Africa contains two parts:

  1. Statistics for Africa: A series of two modules teaching introductory statistics to African users:

  2. Statistics for Climatology: A series of three modules for climatologists.

CAST works well on most recent computers. However it is important to install Java support in some recent versions of Internet Explorer. Java was developed by Sun Microsystems and Java can be installed from their main Java web site http://java.com.

University of KwaZulu Natal

A number of GenStat data sets have been provided by Harvey Dicks that he has used in courses on experimental design. These offer a number of examples, mainly from agronomy, that might be used in practical sessions. The data sets cover factorial, incomplete, Lattice, Row-column designs and GxE and covariance analysis. The data sets can be opened with University of KwaZulu Natal. Each data set is opened by GenStat. Descriptions of the contents of the data files can be obtained via Spread Sheet Title.

University of Reading (SSC)

Contents

1. Guides on good statistical practice
2. Case studies of good statistical practice
3. SSC-Stat - an add-in for Microsoft Excel
4. Other resources for Excel users
5. InStat – an interactive statistical package
6. Statistical games

The Statistical Service Centre (SSC) of the University of Reading, UK, has developed a variety of biometric material relevant to the audience of this Teaching Resource. SSC specialises in statistical training and consultancy in the developing world.

1. Guides on good statistical practice

DFID funded the production of a series of guides on good statistical practice intended primarily to give help to research and support staff in development projects. They include guides on planning, data management, analysis and presentation, and we feel that teachers will also find them useful and complentary to our teaching guides.

General Overview

Statistical Guidelines for Natural Resources Projects

Guides on Planning

Concepts Underlying the Design of Experiments

Some Basic Ideas of Sampling

Guidelines for Planning Effective Surveys

On-Farm Trials - Some Biometric Guidelines

One Animal per Farm

Guides on Data Management

Data Management Guidelines for Experimental Projects

Excel for Statistics: Tips and Warnings

Disciplined Use of Spreadsheet Packages for Data Entry

The Role of a Database Package in Managing Research Data

Project Data Archiving - Lessons from a Case Study

Moving on from MSTAT (to GenStat)

Guides on Analysis

Confidence and Significance: Key Concepts of Inferential Statistics

The Statistical Background to ANOVA

Modern Approaches to the Analysis of Experimental Data

Approaches to the Analysis of Survey Data

Modern Methods of Analysis

Mixed Models and Multilevel Data Structures in Agriculture

Guides on Presentation

Informative Presentation of Tables, Graphs and Statistics

2. Case studies of good statistical practice

The SSC took up a suggestion by DFID to review a number of research projects with a view to producing case studies of good statistical practice. Eight case studies have been produced, intended as illustrative examples to help researchers in their research and development work.

  1. Good practice in well-linked studies using several methodologies - based on a CPP project in the Philippines.

  2. Good practice in survey design and analysis - based on a CPP project in India.

  3. Good practice in on-farm studies - based on a joint NRSP/CPP project in Bolivia.

  4. Good practice in researcher and farmer experimentation - based on an NRSP project in Zimbabwe.

  5. Determining the effectiveness of a proposed sample size - based on work for DFID by a private sector research firm in Bangladesh.

  6. Good practice in data management - based on a bilateral project in Malawi.

  7. Good practice in the preparation of research protocols- based on (i) a Plant Sciences Research programme project in West Africa; (ii) an NRSP project in Nepal; and (iii) an NRSP project in Bangladesh.

  8. Developing a sampling strategy for a nationwide survey in Malawi - based on a bilateral project in Malawi.

3. SSC-Stat - an add-in for Microsoft Excel

SSC-Stat is is an add-in for Microsoft Excel.  Many researchers use Excel for data entry, so it is logical to build on that and add some features often needed for statistical analysis. SSC-Stat is designed to strengthen those areas where the spreadsheet package is already strong, principally in the areas of data management, graphics and descriptive statistics.  SSC-Stat enables graphs (etc.) to be easily generated for datasets in which there are columns indicating different groups.  Menu features within SSC-Stat can:

Use of SSC-Stat implies acceptance of SSC's terms and conditions (pdf file). Please read these installation instructions before attempting to install SSC-Stat. To install SSC-Stat click SSC-Stat version 2.12 (setup file, 6.3MB) Included in the setup, but also available separately:

4. Other resources for Excel users

A number of guides are included for different aspects of Excel usage. These include advice on the use of Excel for statistics, for tables and graphics.

5. InStat – an interactive statistical package

Instat is a general statistical package developed by SSC. It is simple enough to be useful in teaching statistical ideas, yet has the power to assist research in any discipline that requires the analysis of data.

Instat has been used widely in the UK and elsewhere by a range of companies, research institutes, schools, colleges, universities and private individuals. It has been used extensively at SSC and the University of Reading School of Applied Statistics in their applied biometrics courses.

Instat is designed to support the teaching of statistics and provides a relatively gentle introduction to using statistics packages. Teachers may like to use it as a suitable "stepping-stone" towards the use of GenStat. Indeed two of the Case Studies in the Biometrics and Research Methods Teaching Resource (Case Study 7 and Case Study 11) use Instat for part of the analyses.

Instat contains many special facilities for the analysis of climatic data supported by a 400 page guide included with the package as a help file. Case Study 7 demonstrates some of these facilities. Instat has formed the basis for numerous agro-climatology training courses, in the UK, Kenya, Niger, Algeria, Syria, the Philippines and elsewhere

The full version of Instat may be downloaded. There is no copy-protection, time limit or data restriction, other than Instat's inherent size limitations. Individuals may use Instat at no cost, provided that it is for non-commercial purposes. Use of Instat implies acceptance of our terms and conditions (pdf file, 95KB)

Please read these installation instructions before attempting to install Instat.

To install Instat click Instat v3.33 (msi file,45MB)

Included in the setup, but also available separately:

6. Statistical games

These games are simulation exercises based on real life problems that have been adapted at Reading for educational purposes. They started life as index cards in envelopes and cardboard boxes, but are now available as electronic versions. There are four games as follows: