Lecture 9

# Lecture 9 - POL2156B FOUNDATIONS OF RESEARCH DESCRIPTIVE...

This preview shows pages 1–13. Sign up to view the full content.

This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document

This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document

This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document

This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document

This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document

This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: POL2156B FOUNDATIONS OF RESEARCH DESCRIPTIVE STATISTICS LECTURE PLAN • Why use descriptive statistics? • Measures of central tendency • Measures of variability • Cross-tabulation DESCRIPTIVE STATISTICS • Statistics are basically a collection of techniques for dealing with sets of numbers: organizing, summarizing, interpreting numbers. • Here, we are focused on the summarizing part: methods for finding a number that describes a group of numbers. These are called descriptive statistics. FROM THE HEADLINES “A criminal crackdown and greater public awareness are needed to combat the growing problem of elder abuse in Canada, which leaves thousands of seniors „wounded and frightened‟ every year, a new study says” “The report estimates that 400,000 seniors are abused each year in Canada…” Bruce Campion-Smith, “Elder abuse a hidden crime, MPs say” Toronto Star November 17, 2011 “Canadian taxpayers forked out almost \$2 million – including more than \$1,600 to remove a bed – to spruce up a luxury Muskoka resort for last year‟s G8 summit.” Joan Bryden, “G8 Spending included \$1,650 to remove bed, \$3,500 to move light fixtures,” The Globe and Mail November 21, 2011 WHY DESCRIPTIVE STATISTICS? • Why use statistics to describe evidence? • One reason is clarity of communication (and specifically, clarity of claims) • Descriptive statistics can help us put those claims in context NOMINAL MEASURE a measure with categories or classes of attributes, where no values (numbers) are assigned to categories, or the values assigned to each category have no special meaning (e.g. Vote Choice: Conservative, Liberal, NDP, BQ, Green) ORDINAL MEASURE (Assigned Highest Value) High Religiosity (Assigned Middle Value) Moderate Religiosity (Assigned Lowest Value) Low Religiosity A measure where observations are ranked according to their order. The different attributes represent more or less of something. INTERVAL MEASURES 60 years old 50 years old 40 years old 30 years old 20 years old 10 years old 0 years old There is an equal space between each value (e.g. the difference between 50 and 60 years old is exactly the same amount of time as between 20 and 30 years old) WHAT THE DATA LOOK LIKE ID Q1 Q2 Q3 Q4 Q5 Q6 Q7 Q8 Q9 01 1 2 10 5 02 1 2 8 7 03 1 2 9 04 3 4 8 05 2 5 9 06 3 5 8 07 2 3 8 08 2 1 7 09 3 3 4 CASES VARIABLES WHAT’S IN A DATASET? • Data for each observation are “coded” • Variables (Q1, Q2, and so on) are in columns • Cases (e.g. individuals, countries, or time points) are in rows (identified by an ID number) • Each number in each cell represents a specific category on a specific variable for a specific case Childcare Data Country 1 Child vs. 0 2+ Children vs....
View Full Document

## This note was uploaded on 01/31/2012 for the course POL 2107 taught by Professor Bourgault during the Spring '08 term at University of Ottawa.

### Page1 / 46

Lecture 9 - POL2156B FOUNDATIONS OF RESEARCH DESCRIPTIVE...

This preview shows document pages 1 - 13. Sign up to view the full document.

View Full Document
Ask a homework question - tutors are online