# Interpreting Regression Coefficients

2017-05-15

When we read the list of coefficients, here is how we interpret them:

• The intercept is the starting point – so if you knew no other information it would be the best guess.

• Each coefficient multiplies the corresponding column to refine the prediction from the estimate. It tells us how much one unit in each column shifts the prediction.

• When you use a categorical variable, in R the intercept represents the default position for a given value in the categorical column. Every other value then gets a modifier to the base prediction.

Linear regression is easy, but the real value here is Steph’s explanation of logistic regression coefficients.

## Multi-Shot Games

2017-05-26

Dan Goldstein explains a counter-intuitive probability exercise: Peter Ayton is giving a talk today at the London Judgement and Decision Making Seminar Imagine being obliged to play Russian roulette – twice (if you are lucky enough to survive the first game). Each time you must spin the chambers of a six-chambered revolver before pulling the trigger. […]

## Visualizing Emergency Room Visits

2017-05-26

Eugene Joh has a great blog post showing how to parse ICD-9 codes using regular expressions and then visualize the results as a treemap: It looks like there is a header/title at [1], numeric grouping  at [2] “1.\tINFECTIOUS AND PARASITIC DISEASES”,  subgrouping by ICD-9 code ranges, at [3] “Intestinal infectious diseases (001-009)” and then 3-digit ICD-9 […]