HTHSCI 3C04 Chapter Notes - Chapter 10: Recall Bias, Social Desirability Bias, Level Of Measurement
27 Mar 2018
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Variables: various aspects of health that can be measured. Independent variables: interventions; variables under the control of investigators (in treatment study) Dependent variables: outcomes; variables that may be influenced by the independent variable (in treatment study) In a causation study, investigators rely on natural variation between both variables and look for a relation between the independent and dependent variables. Nominal (categorical) variables: names of categories (ex. race (white, black, hispanic, etc. )); number of categories can be determined by the researcher (ex. race defined as two values, black or non-black); no hierarchy is presumed i. e. left-handed is not twice as good as being right-handed. Dichotomous variables: nominal variables that have only two possible values (ex. handedness (left or right), survival (alive or dead), presence or absence of condition/disease) Interval variables: consist of an ordered set of categories, with the additional requirement that the categories form a series of intervals that are all exactly the same size (ex.
