Provide a substantive contribution that advances the discussion in a meaningful way by identifying strengths of the posting, challenging assumptions, and asking clarifying questions. Your response is expected to reference the assigned readings, as well as other theoretical, empirical, or professional literature to support your views and writings. Reference your sources using standard APA guidelines.
Confidence interval is a range of values that the majority of the sample will most likely fall between (Warner, 2013). The level of confidence, either 90%, 95%, or 99% is a probability selected to make the calculation (Warner, 2013). Warner (2013) notes that 95% is the most used confidence level (p. 72). I visualize confidence intervals as an umbrella that the majority will likely be included under.
Confidence intervals are used in statistical analysis to show where the majority of the data will fall (Warner, 2013). For example, if the sample mean of the first English class to take an exam was 88, then I could calculate the score range that 95% of the rest of the classes testing that day will fall in to.
The Publication Manual of the American Psychological Association recommendation to include confidence intervals in research results to remind readers that the results of inferential statistics is unknown and subject to sampling error (Warner, 2013). You cannot use a convenience sample to make an inference about other populations because they do not represent the actual population (Warner, 2013).
Warner, R. (2013). Applied Statistics. 2nd ed. Thousands Oak, CA: Sage.