# Tag Archives: sample size

## How to Tell if a Political Poll is Legitimate￼

Four things to look for. Why People Hate Polls It’s probably true that everybody has taken a survey at some point or other. What’s also probably true is that most people think polling is easy. And why not? Google has … Continue reading

Posted in Uncategorized | | 1 Comment

## Dare to Compare – Part 2

Part 1 of Dare to Compare summarized several fundamental topics about statistical comparisons. Statistical comparisons, or statistical tests as they are usually called, involve populations, groups of individuals or items having some fundamental commonalities. The members of a population also … Continue reading

## Regression Fantasies

Common Reasons for Doubting a Regression Model Finding a model that fits a set of data is one of the most common goals in data analysis. Least squares regression is the most commonly used tool for achieving this goal. It’s … Continue reading

## Polls Apart

Election season is fast approaching so you can be sure a plethora of polls will soon be adding to the mayhem. Polls educate us in two ways. They tell us what we, or at least the population being polled, think. … Continue reading

Posted in Uncategorized | | 4 Comments

## Six Misconceptions about Statistics You May Get From Stats 101

When you learn new things, you can develop misconceptions. Maybe it’s the result of something you didn’t understand correctly. Maybe it’s the way the instructor explains something. Or maybe, it’s something unspoken, something you assume or infer from what was … Continue reading

Posted in Uncategorized | | 10 Comments

## Grasping at Flaws

Even if you’re not a statistician, you may one day find yourself in the position of reviewing a statistical analysis that was done by someone else. It may be an associate, someone who works for you, or even a competitor. … Continue reading

## Secrets of Good Correlations

If you’ve ever seen a correlation coefficient, you’ve probably looked at the number and wondered, is that good? Is a correlation of -0.73 good but not a correlation of +0.58? Just what is a good correlation and what makes a … Continue reading

## You Can Lead a Boss to Data but You Can’t Make Him Think

The most carefully planned data analysis may not survive the intervention of a boss (or a client or other reviewer), whether well intentioned or not. Your aim may be to generate sound data and conduct a thorough and valid analysis, … Continue reading

Posted in Uncategorized | | 3 Comments

## Ten Fatal Flaws in Data Analysis

1. Where’s the Beef? In a way, the worst flaw a data analysis can have is no analysis at all. Instead, you get data lists, sorts and queries, and maybe some simple descriptive statistics but nothing that addresses objectives, answers … Continue reading

## Samples and Potato Chips

Samples are like potato chips. You’re never satisfied with just one. Every one you take makes you want more. And you’re never sure you’ve had enough until you’ve had way too many.   Betcha Can’t Take Just One One observation. … Continue reading