Experimental and Quasi-Experimental DesignThere are basically two main categories of measurement variables with a sample of participants or subjects: experimental and quasi-experimental. According to (Hopkins, 2008), research studies can be conducted using body tissues, cells, animals, or humans. The researcher looks for a relationship between the variables and this can be achieved using statistics, relative frequencies and/or correlations (Hopkins, 2008). You can achieve this by simply observing without influencing, manipulating or controlling the environment or interaction. You can observe and explore a topic, or you can compare one subject with another (Hopkins, 2008). Experimental study The objective of this study is to find out whether the intervention of using relaxing music can have an impact on the emotional state. The hypothesis of this study asks to what extent does listening or not listening to music before a test decrease test anxiety in middle school students? The second hypothesis is: To what extent does listening or not listening to music increase test scores in middle school students? If the hypotheses are supported, then students will not only report a decrease in physical and emotional symptoms of anxiety, but will obtain higher scores than the average of the three previous tests. This means that a decrease in anxiety will occur after the intervention, and a decrease in anxiety will produce a higher score. The decrease in one variable and the increase in the other is known as a negative correlation (Cozby and Bates, 2012). This means that there is a relationship between the two variables. Of course, this does not have to be demonstrated only by statistics and...... middle of paper ......and Research. Journal of the Operating Room Nurses Association, 90, 543-551. doi:200698620Blankinship, D. G. (2011, January 13). Testing for anxiety: Researchers find solution to help students deal with it. Huffington Post Education. Retrieved from http://www.huffingtonpost.com/2011/0114/testing-anxiety-research_n_809221.htmlCozby, P. C., & Bates, S. C. (2012). Methods in behavioral research (11th ed.). New York, NY: McGraw Hill.Fiske, S. T. (2010). Social beings: Fundamental motivations in social psychology (2nd ed.). Hoboken, NJ: John Wiley & Sons, Inc. Hopkins, W. G. (2008). Quantitative research design. Sports Science, 4(1). Retrieved from http://www.mendeley.com/research/quantitative-research-design-5/Smith, R. A., & Davis, SF (2007). The psychologist as detective: An introduction to conducting research in psychology (4th ed.). Upper Saddle River, NJ: Pearson Prentice Hall.