Regression Analysis: A Guide to Modeling Predictive Relationships
Regression
Regression is a well-known statistical technique used to model the predictive relationship between several independent variables (DVs) and one dependent variable. The objective is to find the best-fitting curve for a dependent variable in a multidimensional space, with each independent variable being a dimension. The curve could be a straight line, or it could be a nonlinear curve. The quality of fit of the curve to the data can be measured by a coefficient of correlation (r), which is
Read MoreSimple Linear Regression
BIOS 7020: Introductory Biostatistics II Fall 2018
Hanwen Huang, Ph.D.
Department of Epidemiology & Biostatistics
College of Public Health University of Georgia huanghw@uga.edu
Data Summaries (Mean, Median, . . .) Introduction to Probability
Inference for one sample problem: estimates, CIs and tests for
continuous response: mean binary response: proportion
Inference for two sample problem: estimates, CIs and tests for
continuous response: mean binary response: proportion
Sampling Methods and Concepts: A Comprehensive Guide
Sampling Methods and Concepts
Sampling Error
Any difference between the characteristics of a sample and the characteristics of a population. The larger the sampling error, the less representative the sample.
Target Population
A set of elements larger than or different from the population sampled and to which the researcher would like to generalize study findings.
Representative Sample
A sample that “looks like” the population from which it was selected in all respects that are potentially relevant
Read MoreAccrual Accounting: Principles and Applications
Which of the following statements about the accrual-basis of accounting is false?
| Events that change a company’s financial statements are recorded in the periods in which the events occur. |
| Revenue is recognized in the period in which services are performed. |
| Accrual-basis is in accordance with generally accepted accounting principles. |
| Revenue is recorded only when cash is received, and expense is recorded only when cash is paid. |
Statistical Concepts: A Comprehensive Guide to Measures, Tests, and Relationships
Measures of Central Tendency and Variability
Nominal, Ordinal, Interval, and Ratio Scales
Nominal = qualitative number, categories, no numerical relationship between categories, Ordinal = ranking of categories, do not know how much greater each category is, Interval = continuous (magnitude difference between two values can be determined), placement of zero is arbitrary (e.g., Celsius), Ratio = continuous, zero has a natural interpretation
Sampling Distribution
A sampling distribution is a probability
Read MoreMathematics Cheat Sheet: Derivatives, Vectors, Probability, and More
Derivative Table
f (x) = K f ‘(x) = 0
f (x) = x f ‘(x) = 1
f (x) = kx f ‘(x) = k
f (x) = kx + b f ‘(x) = k
f (x) = xn f ‘(x) = nxn-1
f (x) = u (x) + v (x) f ‘(x) = u’ (x) + v ‘(x)
f (x) = u (x) * v (x) f ‘(x) = u (x) * v’ (x) + v (x) * v ‘(x)
f (x) = u (x) / v (x) f ‘(x) = [v (x) * u’ (x) – u (x) * v ‘(x)] / [v (x)]2
f (x) = [u (x)]n f ‘(x) = n[u (x)]n-1 * u’ (x)
f (x) = sin x f ‘(x) = cos x
f (x) = sin [u (x)] f ‘(x) = cos u * u’
f (x) = cos x f ‘(x) = – sin x
f (x) = cos