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The meaning of numbers 90 The number correct on a test out of 100 The last two digits of your SSN The percentile you scored on the SAT

Nominal Scale Are not really scales at all They do not scale items along any dimension, but rather label them Numbers are used as names and have no quantitative value

Nominal Scales Gender Political party Your SSN Religion

Ordinal Scales Has the characteristics of the nominal scale PLUS: the characteristic of indicating greater than or less than i.e., RANK ORDER

Ordinal Scales Rank of professor Your place in a foot race Saying “This class is smaller then my other class”

Interval Scales Has the properties of BOTH the nominal and ordinal scales PLUS: the intervals between the numbers are equal e.g., the distance between 4 and 5 is the same distance between 1 and 2

Interval Scales Temperature Problem: What does 0o F mean? the difference between 10o F and 20o F is the same as the difference between 80o F and 90o F Problem: What does 0o F mean? With interval scales you CAN NOT make ratio statements

Interval Scale 50 70 10 30 80 20 40 60 Appears twice as large

Interval Scale 30 50 -10 10 60 -20 20 40 Now it appears three-times as large!

Ratio Scales Has all the characteristics of the nominal, ordinal, and intervals scales PLUS: it has a true zero point This zero point indicates a complete absence of the thing measured

Ratio Weight Height Speed Distance

Features of the four scales

Why are the types of scales important? They help you understand what type of statistic to use

Practice Inches on a yardstick Drivers licenses number Dollars as a measure of income Order of finish in a car race Intelligence test scores

1) Is depressed, blue 2) Is not relaxed, does not handle stress well 3) Can be tense

4) Worries a lot 5) Is easily upset

Neuroticism Raw Score Add your answers What does your score mean? Your score can range between 5- 25 What does your score mean? Note: It is meaningless unless you know how others scored

Simple Frequency Distribution 1) Find the highest and lowest scores 2) Write in descending order all the numbers from 24 to 6

Simple Frequency Distribution 3) Start with the number in the upper-left corner, draw a line under it, and place a tally mark in the frequency distribution 4) Do this with all the data 5) Count the number a tally marks

Group Frequency Distribution Scores are grouped into equal-sized ranges called “class intervals” Usually want around 10 class intervals

Practice Book page 34 # 2.1 (women) # 2.3