Question 1
Descriptive research purposes to describe the characteristics of a given population or a phenomenon that is of interest to a researcher. It is also referred to as statistical research. Descriptive research is systematic, factual and accurate. In descriptive research, the researcher does not evaluate causal relationships between variables. Therefore, the internal validity requirement for this kind of research is low. Descriptive research relies on measures of central tendency and dispersion, frequency distribution and graphs. On the other hand, inferential research aims at making predictions about a given population from a sample that the researcher analysed. In inferential research, the researcher evaluates causal relationships and cause and effect between variables. Therefore, the internal validity requirement for this kind of research is high. Inferential research uses inferential statistics such as regression analysis, correlation analysis, ANOVA, survival analysis among others.
Survey research is a descriptive design. This is because in survey research method participants are required to answer questions which have been administered through questionnaires or interviews. The researcher then describes the responses that were given by the participants. The researcher does not attempt to identify causal relationships or cause and effect. Experimental research is an inferential research design. In experimental research, one or several variables are manipulated and changes in the other variables are measured. Experimental research seeks to identify cause and effect. Non-experimental research is an inferential research design. In non-experimental research, researchers observe and measure items as they are without manipulating them. Although the researcher does not manipulate the variables or research items, they still interpret the obtained results to conclude some form of relationships between the variables of interest.
Question 2
There is a need for hypotheses in inferential approach because it attempts make predictions about a given population from a sample. In inferential approach, the researcher evaluates causal relationships between variables or cause and effect. Therefore, there is a need for hypothesis. There is no need for hypotheses in descriptive approach because the researchers observe and measure items as they are. In descriptive approach, the researcher neither evaluates causal relationships between variables nor cause and effect.
Question 3
Research alignment is important in order to address the research objectives. For example if the researcher intends to measure cause and effect the most appropriate design would be experimental design. Researchers need to align their research in order to adequately plan for the research and properly address the research objectives.
Question 4
Experimental and quasi experimental research designs are used when one or several variables are manipulated and controlled by the researcher in order to estimate cause and effect. A true experimental design is used when participants to groups are assigned randomly whereas a quasi-experimental design is used when participants to groups are not assigned randomly.
Question 5
The three research designs have been defined properly and comprehensively. However, we cannot conclude that the purpose of quantitative research is to determine the relationship between at least two variables. Whereas it may be true for experimental and non-experimental research designs it is not true for survey research design. In survey research design the research only describes the data without making any interpretation.
Question 6
There are three main quantitative research designs; experimental design, non-experimental design and survey design. Survey design is descriptive in nature and, therefore, the internal validity requirement for this Kind of research is low. Experimental design and non-experimental designs are inferential in nature and, therefore, the internal validity requirement for this Kind of research is low.
References
Babbie, E. R. (2010). The Practice of Social Research (12 ed.). New York: Cengage Learning.
Sutton, C. D., & David, M. (2010). Social Research: The Basics (revised ed.). New York: SAGE.
