Why the design is disadvantageous?

The four major research designs include experimental, case study, longitudinal, and cross-sectional research design. In experimental design, the researcher controls variables that will determine the result of the experiment. This is based on either randomization or manipulation. It is advantageous to the researcher since he/she has full control over the situation. Therefore, the researcher can determine cause-effect relationships; hence, enabling him/her to distinguish between placebo and treatment effects of the experiment (University of Southern California Libraries, 2016). However, the design is disadvantageous. The researcher may have to rely on artificial results, which may not depict the true nature of phenomena in the real world. Again, it can be costly if special equipment is required and it cannot provide solutions to problems requiring either ethical or technical concepts. An experimental design is appropriate in studying a control group because it provides a rationale for measuring the dependent variables associated with the sample population under study. A case study is a research design involving an in-depth analysis of a typical research problem instead of statistical surveys or comparative inquiry. Therefore, they are useful in assessing issues in the contemporary real-life contexts due to their extensive use of theoretical concepts and methodological extensions (University of Southern California Libraries, 2016). However, their limitations involve the lack of criteria for selecting a case and analysis and interpretation of findings may not solve a given problem. Case studies are appropriate in assessing the performance of students in the classroom settings by analyzing past experiences, especially in multicultural settings. 

Longitudinal research design is where the researcher observes a phenomenon for a long duration repeatedly. The advantage is that one can assess the duration of a given phenomenon. Therefore, he/she can deduce causal explanations and measure existing variables based on description patterns. However, it is advantageous because the methods of collecting data may vary depending on seasons. Also, it requires qualitative research to explain concepts that show great fluctuations. Finally, it can be used to study antisocial groups in society since it provides sufficient time to collect data about the various attributes of introverts, for example. Furthermore, cross-sectional research design measure differences between variables and involves the use of passive approaches to make inferences based on cause-effect relationships (University of Southern California Libraries, 2016). It provides an explicit snapshot of the result and the attributes linked to it. However, it is challenging to identify a sample size with similar characteristics unless the researcher is concerned with one specific variable. Therefore, it is suitable for studying a horizontal group. This is because it can depict the same aspects like wealth and living standards of people in the same social class. 

Reference 

University of Southern California Libraries (2016). University of Southern California 

Research Guides . Organizing Your Social Sciences Research Paper: Types of Research Designs . http://libguides.usc.edu/c.php?g=235034&p=1559832