BST 322 - Intro Study Guide questions and answers (verified for accuracy)

Qualitative Non-numeric or narrative in form Quantitative 1) Numeric, composed of numbers or scores. 2) e.g. blood pressure, weight, age, etc. Variable 1) A characteristic of an individual or group 2) e.g., body temperature, blood pressure, date of birth, or anything else that can be measured Independent Variable 1) Influences the outcome of something; the one you change. In experimental research, this is the variable that is manipulated 2) e.g. placebo vs drug Dependent Variable The outcome of interest, assumed to be influenced by independent variables; the one you measure Dependent Variable Examples 1) Whether or not a subject got cancer (independent variables in this case might include whether or not the subject was a smoker). 2) If the subject developed pneumonia or not (independent variables might include if he or she aspirated). 3) If a neonate is infected with HIV from the mother (the independent variable might be if the mother received AZT during her pregnancy). Discrete Variables 1) Have a finite number of values between two points. Essentially, discrete variables have only integers for values 2) number of children in a household, hospital readmissions, date of birth Continuous Variables 1) Have, in theory, an infinite number of values between two points. Generally, a variable that has decimals or fractions is a continuous variable. 2) Body temperature and pH are continuous variables Levels of Measurement 1) Generally, use highest level of measurement possible as they provide more information and can generally be analyzed with more powerful statistical tools 2) 4 types: a) Nominal b) Ordinal c) Interval d) Ratio Nominal 1) Grouping objects into classes; No "scale" is implied 2) e.g. nationality, gender, marital status, etc. Ordinal 1) Measures that indicate an order (i.e. the relationships can be expressed using or ) 2) The scale does not have equal intervals between the points 3) e.g. Clinical nursing levels, socio-economic status, grades in the military, etc. Interval 1) Measures that indicate an order and have equal intervals between successive points on the scale, but no "true 0." 2) e.g. Temperature in Fahrenheit degrees 3) Cannot really make ratios with it, i.e., 100 degrees is not twice as hot as 50 degrees Ratio 1) Same as "Interval" but has a "true 0." 2) e.g. Pulse rate, temperature in Kelvin degrees 3) In general, we treat interval and ratio variables similarly and they are often referred to as "scale" variables Data Analysis 1) 6 focuses: a) Population b) Sample c) Parameter d) statistic e) Descriptive statistics f) Inferential statistics 2) 3 Variate types: a) univariate (1 variable) b) bivariate (2 variables) c) multivariate (2 variables) Population All the members of a defined group Sample Some of the members of a population Parameter Any decriptive measure of a characteristic of a population (greek letters) Statistic Any descriptive measure of a characteristic of a sample (Arabic letters)