BIOS 2010 Lecture 2: Chapter 2
2 Mar 2017
School
Department
Course
Professor
Document Summary
Drug approval: the fda requires positive results from a clinical trial before approving new drugs. Allocation of resources assessing risk factors for disease. Continuous- can take any real numerical value over and interval. Data are continuous if between any two possible values, we can also find another possible value, ex: fractions and decimals, age, weight. A categorical variable places an individual into one of several groups or categories. Nominal- qualitative and unordered, ex: hair color, blood type, race. Binary/ dichotomous if values fall into exactly two unordered categories, ex: gender, presence or absence of a disease. Ordinal- naturally ordered categories, ex: stages of cancer, age, letter grades, likert scales. Counts are sometimes referred to as frequencies, often. Counts are sometimes referred to as frequencies, often denoted as n. Frequencies are appropriate for comparison only when the groups have the same total. Proportions are sometimes referred to as relative frequencies.
