REACH Dictionary
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1 Scale
A scale is an instrument that measures qualitative constructs through the representation of those constructs in quantitative metric units. For example, a researcher investigating life satisfaction may have participants respond on a scale of 1-5, where 1 denotes "low life satisfaction" and 5 denotes "high life satisfaction."
Secondary data analysis involves the use of previously collected data in a particular research field to study a different research question. Researchers can recycle data from one article or combine data from various studies to create a new, larger sample as well.
Lewis-Beck, M., Bryman, A., & Liao, T. (2004). The SAGE encyclopedia of social science research methods (Vols. 1–3). Thousand Oaks, CA: SAGE Publications. https://doi.org/10.4135/9781412950589
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Study methods and variables
Selection bias occurs when a sample is not selected randomly, whether accidentally or deliberately, and thus does not provide an accurate representation of the population.
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Errors and biases
Selection effects are correlations between a characteristic of the study subject and the presence of an observer, thus resulting in biased data.
Sandberg, A (n.d.). Observer selection effects [PDF file]. Retrieved from https://www.fhi.ox.ac.uk/wp-content/uploads/W6-Observer-selection-effects.pdf
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Errors and biases
Self-report measures are those in which study participants record their responses to a survey or questionnaire on their own. These measures risk social desirability bias, as participants may report more socially appropriate responses rather than the truth.
Semi-structured interviews are a data collection method for qualitative research, in which interviewees are asked questions about overarching themes rather than a from a script of questions, which allows participants to present responses relevant to the themes in question and potentially present unexpected themes as well.
Lewis-Beck, M., Bryman, A., & Liao, T. (2004). The SAGE encyclopedia of social science research methods (Vols. 1–3). Thousand Oaks, CA: SAGE Publications. https://doi.org/10.4135/9781412950589
7 Service
A service is "a branch of the Armed Forces of the United States, established by act of Congress, which are: the Army, Marine Corps, Navy, Air Force, and Coast Guard."
Office of the Chairman of the Joint Chiefs of Staff. (2019). Dictionary of Military and Associated Terms. Washington DC: The Joint Staff.
The Sexual Assault Prevention and Response Program is "a Department of Defense program for the Military Departments and Department of Defense components that establishes sexual assault prevention and response policies to be implemented worldwide."
Office of the Chairman of the Joint Chiefs of Staff. (2019). Dictionary of Military and Associated Terms. Washington DC: The Joint Staff.
Single-item measures, also referred to as one-item questions, consist of measuring tools used by researchers that contain only one question. These measures include scales which rank the participants' responses (e.g., a pain scale from no pain to the worst pain ever).
Moss, S. (2016, May 27). Single item measures. Retrieved March 4, 2019, from https://www.sicotests.com/psyarticle.asp?id=97
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Study methods and variables
A skewed distribution refers to a distribution that is asymmetrical and not centered on the mean. Skewed distributions may be positively skewed, where the ""tail"" extends to the right, or negatively skewed, where the ""tail"" extends to the left. Skewed distributions indicate that deviations will be higher or lower than the normal distribution's mean.