The Research Design
Experimental Design Definition A description of what a researcher would like to find out and how to find it out. Pre-requisites 1.Identification of problem 2.Formulation of hypothesis 3.Detailed description and explanation of the procedure of the experiment.
Experimental Procedure 1.Selection of appropriate materials for the test. 2.Specification of the variable to be measured. 3.Selection of procedure to be used to measure the identified variables. 4.Specification of the procedure that will be used to test whether the data supports the hypothesis or not.
Research Design Description A complete sequence of steps or procedures that need to be followed when obtaining the required data during an investigation. Significance of the Research Design Serves as a guide during the conduct of an experimental investigation Minimizes cost Maximizes gained information relevant to the problem
Research Design is… embodie d in a research proposal Parts of a Research Proposal 1.Introduction 1.Background of the Study 2.Statement of the Problem 3.Significance of the Study 4.Scope and Limitations of the Study 2.Review of Related Literature 3.Methodology 4.Bibliography
Points to Remember Subject – Also known as the experimental unit – May be a person, animal, plot, device, etc. – May be subjected to different treatments (experimental research) or to pure observation only (descriptive research) Treatment – Any procedure done on an experimental unit
Principles of Research Design Replication Repetition Allows estimating variations among variations in the subject possible. Necessary to conduct statistical test of significance Randomization Assignment of experimental subjects to treatments by chance. Done to create equivalent groups prior to the experiment Reduces possible biases
Principles of Research Design Local Control Grouping subjects into blocks or units that are relatively homogeneous. Control of Extraneous Variables Ensures that identical conditions are provided to the experimental and control groups except for the absence (control) and presence (experimental) of the treatments.
Types of Research Design
Completely Randomized Design (CRD) Treatments are assigned randomly to experimental subjects without restrictions Is used when the subjects are homogeneous The loss of information due to missing observation is small compared to other designs. Used in single-factor experiments
Randomized Complete Block Design Divides the experimental subjects into more or less homogeneous groups called designs. Appropriate when subjects can be categorize according to certain characteristics and when a few dropouts are expected. Used when randomization will tend to produce groups which are not nearly equivalent for comparison.