Research Design UNIT Ii

 A research design is a systematic plan to study a scientific problem.  It is a blueprint that is followed in completing a study.  A research project conducted scientifically has a specific framework of research from the problems identification to the presentation of the research report.  This framework of conducting research is known as research design.

Research Design The research design is the master plan specifying the methods and procedures for collecting and analyzing the needed information.

1. Exploratory Research Design  Secondary Data / Literature  Focus Groups  Case Study 2. Conclusive Research Design A) Descriptive Research i. Longitudinal study ii. Cross-sectional study B) Experimentation i. Laboratory experiments ii. Field experiment C) Casual Research i. Natural ii. Controlled

 In scientific studies, experimental design is the gold standard of research designs.  The experimental method is a systematic and scientific approach to research in which the researcher manipulates one or more variables, and controls and measures any change in other variables.  Experimental Design is effective in measuring the cause and effect relationships.

Aims of Experimental Research  Experiments are conducted to be able to predict phenomenon.  Typically, an experiment is constructed to be able to explain some kind of cause.  Experimental research is important to society it helps us to improve our everyday lives. society

DEVELOPING A RESEARCH PLAN Before conducting any research, you should develop a research plan. The research plan should include the overall purpose of the research and how the outputs will be used and communicated The types and sources of data needed The means by which the data will be collected and analysed The scale of research (i.e. the numbers and spread of the research subjects ) The resources available (including time); and, a clear indication of the stakeholders in the process.

Basically, the research plan should provide answers to the following questions.  What are you trying to find out?  Who or what are you interested in?  Is the information already available?  Where is the best place to obtain the information?

The research plan serves very important functions: ◦  It contributes to your development as an investigator ◦  It s a map for your dissertation ◦  It demonstrates your intellectual vision and aspirations ◦  It's also an opportunity to begin to demonstrate the creative and independent thinking required of a successful research professional Research Plan Functions

Sampling is concerned with the selection of a subset of individuals from within a statistical population to estimate characteristics of the whole population. Each observation measures one or more properties (such as weight, location, color) of observable bodies distinguished as independent objects or individuals.

Saves time and effort Saves money More accurate measurements Only way for destructive enumeration Only way when population contains infinitely many members Enables to estimate sampling error and hence helps in obtaining information concerning characteristics of the population

 Defining the population of concern  Specifying a sampling frame, a set of items or events possible to measuresampling frameset  Specifying a sampling method for selecting items or events from the framesampling method  Determining the sample size  Implementing the sampling plan  Sampling and data collecting  Data which can be selected

A census is a study of every unit, everyone or everything, in a population. It is known as a complete enumeration, which means a complete count. A sample is a subset of units in a population, selected to represent all units in a population of interest. It is a partial enumeration because it is a count from part of the population. Information from the sampled units is used to estimate the characteristics for the entire population of interest.

A population may be studied using one of two approaches: taking a census, or selecting a sample. It is important to note that whether a census or a sample is used, both provide information that can be used to draw conclusions about the whole population. Once a population has been identified a decision needs to be made about whether taking a census or selecting a sample will be the more suitable option. There are advantages and disadvantages in using a census or sample to study a population:

Step 1: Target population must be defined The target population should be defined in the light of a research objective. Target population is the collection of objects, which possess the information required by the researcher and about which an inference is to be made. Improper definition of the target population will lead to misleading results which might prove dangerous for a researcher. Therefore, target population must be defined very carefully. The research objective should be the most important factor to be taken into account while deciding on the target population. However, other parameters like time and cost should not be ignored.

Step 2: Sampling Frame must be determined A researcher takes a sample from a population list, directory, map, city directory, or any other source used to represent the population. This list possesses the information about the subjects and is called the sampling frame. It might seem that the target population and the sampling frame are the same, however, in reality, there is a reasonable difference between the two.

For understanding this difference, let us take the example of a telephone directory. A telephone directory possesses information about a particular region. When we take a sample on the basis of information available in a directory, there is a possibility that this will not give us true information. It is always possible that few subjects in that region may not have telephones, few subjects may have changed their residence and this information might not have been updated in the telephone directory. Similarly, some subjects may have multiple listings under different names; some subjects may have changed the numbers ever since the directory was printed.

Sampling is carried out on the sampling frame and not on the target population. Theoretically, the target population and the sampling frame are the same, however, in practice, sampling frame and target population are often different. Over-registered sampling frames contain all the units of target population plus some additional units. Under-registered sampling frames contain fewer units as compared to the target population. A researcher’s objective is to minimize the differences between the sampling frame and the target population.

Step 3: Appropriate sampling technique must be selected Selecting a sampling technique is a crucial decision for a researcher. A researcher has to decide between the Bayesian or the traditional sampling approach, sampling with or without replacement, and whether to use probability or non-probability sampling techniques. The traditional approach is more appealing and is widely used. In the traditional approach, the entire sample is selected before data collection begins. In sampling with replacement, an element is selected from the frame, the required information is obtained, and then the element is placed back in the frame. This way, there is a possibility of the element being selected again in the sample. As compared to this, in sampling without replacement, an element is selected from the frame and not replaced in the frame. This way, the possibility of further inclusion of the element in the sample is eliminated.

Step 4: Sample size must be determined Sample size refers to the number of elements to be included in the study. While deciding the sample size, various qualitative and quantitative aspects must be considered. The nature of research and analysis is an important consideration while deciding the sample size. For qualitative research, a small sample size is sufficient. For conclusive research, a larger sample is required. Sophisticated statistical analysis is also a foundation for taking a decision about the sample size. The statistical analysis techniques applied for analyzing small and large samples are different. The cumulative errors across variables are reduced in a large sample. Time and resources are the two constraints on which the sample size of every research study is based. Sample size should also be adjusted with respect to factors such as eligible respondents and the completion rate.

Step 5: Sampling process must be executed The execution of sampling techniques requires detailed specification of target population, sampling frame, sampling techniques, and the sample size. At this stage, each step in the sampling process must be effectively executed.

 to the truth