RESEARCH DESIGN

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C E O C H O N O G O R

O C H O N E C @ U N I S A . A C . Z A

I N S T I T U T E F O R S C I E N C E A N D T E C H N O L O G Y E D U C AT I O N

U N I V E R S I T Y O F S O U T H A F R I C A , P R E T O R I A

AT T H E

I S T E I N T E R N AT I O N A L C O N F E R E N C E O N S C I E N C E A N D T E C H N O L O G Y E D U C AT I O N, 2 4 O C T O B E R , 2 0 1 3

Meaning of Research Design Justification for research design in a

research process Types of Research Designs Forms of Quasi-Experimental Designs Mixed methods designs

To be considered are:

As the structural scaffold of a research

Is the plan, structure and strategy of investigation conceived so as to obtain answers to research problems and to control variance (Kerlinger)

Meaning of Research Design

A good research design enables the researcher to carry out research in a proper and systematic way

It gives direction the course of the research

It gives credibility to the results of a given research (increasing maximum efficiency and reliability)

It acts as a firm foundation for the entire research

Justification for research design in a research process

Reduces inaccuracy

eliminates bias and marginal errors

Determines the type of analysis and testing of hypothesis to be done with data collected

Determines the type of statistical tools required to analyse the collected data.

Justification for research design in a research process cont`d

Types of Research Designs

Types of Research Designs Cont`d

R shows randomised group

O is observation or measure

N is Non-equivalent group

X is treatment or programme

C is for control group(s) where applicable

Design Notations

X O The One-Shot Case Study Design Multigroup Posttest-Only Design

Experimental Group 1 X O1

Experimental Group 2 X O1

Experimental Group 3 X O1

Experimental Group 4 X O1

Some Design Representations

• Longitudinal Case Study Design

X O1 O2 O3 ….On

• One-Group Pretest Postest Design O1 X O2

• Static-Group Comparison or Comparison Group Posttest-Only Design

Experimental Group X O1

Comparison Group O1

Some Design Representations Cont`d

* Randomised One-Group Posttest-Only Design R X O1

• Static-Group Comparison or Comparison Group Pretest Posttest Design

O1 X O2

O1 O2

• Interrupted Time-Series Design O1 O2 O3 X O4 O5 O6

Some Design Representations Cont`d

Descriptive (e.g. case-study, naturalistic observation, survey

Correlational (e.g. case-study , observational study) Semi-experimental (e.g. field experiment, quasi-

experiment) Pre-experimental Designs (One-Shot or One Group

Posttest-Only Design, Multigroup Posttest- Only Design, Longitutidinal Case Design, One-Group Pretest Posttest Design)

Experimental (e.g. experiment with random assignment) – such as the Solomon Four-Group Design and Switching Replications Design.

Types of Research Designs Cont`d

Review (Literature review, Systematic review)

Meta-analytic (Meta-analysis) Ex Post Facto Design

Types of Research Designs Cont`d

MIXED METHODS (QUAN and QUAL) as a methodology involves philosophical assumptions to guide the collection and analysis of data using QUAN and QUAL approaches.

As a method, it focuses on collecting and analysing data using QUAN and QUAL approaches.

Mixed methods designs

Merge the data

Connect the data

Embed the data

(Creswell & Clark, 2007)

Three ways of mixing QUAN AND QUAL DATA

QUAL DATA Results QUAN DATA

QUAL DATA Results

QUANT DATAQUAL DATA

QUAN DATA

Results

Triangulation Design (Simple; Convergence Model; Data Transformation Model; Validating Quantitative Data Model; and Multilevel Model)

Embedded Design (Garacelli & Greene, 1997)

Explanatory Design Exploratory Design

Four major types of Mixed Methods Designs

Non-equivalent Groups Design

Pretest-Posttest Design

Interrupted Time-Series Design (with multiple pretests and multiple posttests- it provides greater confidence that the change in the dependent variable was caused by the manipulation and not just a random fluctuation. (Price and Oswald, 2006, 2008)

Static Group Comparison Control Design

Forms of Quasi-Experimental Designs

Designs may be generally classified into two:

1. Fixed designs

2. Flexible designs

Classification of Research Designs

Where the design of a study is fixed or determined before the main stage of data collection.

It is normally theory driven to determine in advance which variables are to be measured.

It is useful in quantitative and mixed methods researches.

Fixed designs

where variables are not easily measured quantitatively such as culture

Flexible designs

Pretest-Posttest Design: Cannot be completely sure that the observed change in the dependent variable was caused by the manipulation of the independent variable.

The need for a control group.

Some Loop holes

Threats to Validity of Research Designs

History (between the 1st and 2nd second measurements)

Maturation of participants with time Testing effects Instrumentation: disposition of the

observers and scorers could produce changes in outcomes.

Statistical regression (regression to the mean) –

Bias in selection of participants

Factors that affect internal validity

Experimental mortality

John Henry effect

Factors that affect internal validity Cont`d

Single Group Threats

Qualitative titles do not suggest a comparison of groups or a relationship among variables. Rather they EXPLORE one idea (the central phenomenon) for an in-depth understanding leading to formulation of theories.

Quantitative titles compare groups or relate variables. They Test, Predict, Explain and Describe.

Tips for choosing appropriate research design

Title for mixed methods studies suggests a mixed methods approach and foreshadows the type of mixed methods design for the study.

To think of non-equivalent groups design, the groups must be as similar as possible. This helps to minimise or control extraneous variables

Tips for choosing appropriate research design Cont`d

Thank you all