Statistical reasoning vocabulary review Autumn semester 2018

vocabulary Numerical Data is data that is measurable, such as time, height, weight, amount, and so on. Numerical data can be arranged in ascending or descending order. It is possible to find meaningful mean, median and mode for numerical data. Categorical Data represent characteristics such as a person’s gender, marital status, hometown, or the types of movies they like. Categorical data can take on numerical values (such as “1” indicating male and “2” indicating female), but those numbers don’t have mathematical meaning.

vocabulary The Mean refers to the arithmetic average used to derive the central tendency of the data in question. It is determined by adding all the data points in a population and then dividing the total by the number of points. It is possible to find a meaningful mean for numerical data. It is not possible to find a meaningful mean for categorical data. The Median is the middle or central data point(s) of a data set, in which half of the observations are above the median and half are below. If there is an even number of the data points, the median is the average of the central two data points. It is possible to find a meaningful median for numerical data. It is not possible to find a meaningful median for categorical data. The Mode is the observations point which occurs most often. If no point occurs more often than the others, then there is “no mode.”

vocabulary Outliers are an identified observation point that are distant from other observations. An outlier may be due to variability in the measurement or it may indicate experimental error; the latter are sometimes excluded from the data set. Data sets sometimes have a minimum and a maximum outlier though they may just as often have one or the other or have none at all. It is possible for a data set to have more than one minimum or maximum outlier. Univariate is data analysis or statistical analysis that concerns a single variable. Bivariate is data analysis or statistical analysis that concerns two variables. Multi-variate is data analysis or statistical analysis that concerns more than one variable.

vocabulary Sample: A segment or portion of a population used to suggest or represent the characteristics of the entire population. Sub-sample: A smaller segment or portion of a sample based on additional characteristics or parameters. Population: The entire collection of possible observations within defined characteristics or parameters. Sample Area: The physical area or space containing a sample population. Population Area: The physical area or space containing the entire population.

vocabulary Sample mean: The arithmetic average of the combined samples. The sample mean represents the average of all of the samples and can be used to calculate deviations from the mean. Sample density: The number of individual subjects present in a sample area. Density is normally expressed as the number of individuals per area squared or per volume cubed. Population density: The number of individual subjects present in a population area. Density is normally expressed as the number of individuals per area squared or per volume cubed.

vocabulary Experiment: A study in which the researcher the study introduces a element to influence the results. Usually a control group exists to measure the effects of the treatment given to the experimental group. Observation: A study in which the researcher passively observes a population or consults existing information or data and does not attempt to influence the results. Interview / Survey: A study in which the researcher actively participates in collecting data through asking questions. The interviewer may unintentionally introduce bias through the order of the questions or through action. This type of study is the least reliable.