## On p-values and statistical practice!

The following was posted on the American Statistical Association’s discussion forum by Prof. Cobb in 2014

*Q: Why do so many colleges and grad schools teach p = 0.05?*

*A: Because that's still what the scientific community and journal editors use.*

*Q: Why do so many people still use p = 0.05?*

*A: Because that's what they were taught in college or grad school.*

## Solving complex problems

For every complex problem there is a simple solution, and it is wrong.

~ H.L. Menken

## Pattern recognition

Graphical display of data helps to form preliminary hypothesis, observe patterns, etc. However, one should be careful in staring too long at a graph. In the words of Carl Sagan,

*Humans are good, she knew, at discerning subtle patterns that are really there, but equally so at imagining them when they are altogether absent*

## A trend is a trend

A trend is a trend, is a trend, but the question is, will it bend? Will it alter its course, through some unforeseen force and come to a premature end?

~Sir Alec Carincross

*One of the Britain's most distinguished economists and a former chief economic advisor to the British government. (Extracted from J. Johnston and J. DiNardo: Econometric Methods, McGraw-Hill, 2007)*

## Summarizing data

This post is specific to the use of the R language for data analysis. Often, we need a quick look at the data in terms of summary of key variables. The function *str()* tells us about the dimensions of the data frame in terms of the number of observations and the number of variables. Further, it tells us the name of individual variables, their type (class) and list of first few observations.