Social Statistics for a Diverse Society Chapter 5 Terms – Flashcards

A measure of variability for normal variables The IQV is a single number that expresses the diversity of a distribution The IQV ranges from 0 to 1 An IQV of 0 would indicate that the distribution has NO diversity at all An IQV of 1 would indicate that the distribution is maximally diverse IQV= k(100^2-∑Pct^2)/100^2(k-1) k= number of categories ∑Pct^2= the sum of the squared percentages

A measure of variation for interval-ratio data - Indicates the width of the middle 50% of the distribution and is defined as the difference between the lower and upper quartiles IQR= Q3-Q1 Q3=75th percentile Q1= 25th percentile Limitation: Because the interquartile range is based on only two scores, it fails to yield any information from all of the other scores

Central Tendency: Numbers that describe what is typical or average (central) in a distribution Measures of Variability: Number that describe diversity or variability in the distribution Nominal variables --> use IQV Ordinal levels --> Calculate the IQV or the IQR Interval-ratio variables --> Use IQV, IQR, variance/standard deviation

A measure of variation in interval-ration variables. It is the difference between the highest (maximum) and lowest (minimum) scores in the distribtion. Range = Highest score - lowest score Limitations: 1. Distorted by atypically high or low scores 2. No information about variation between high and low scores

The most important and widely used measure of dispersion Should be used with interval-ratio variables but is often used with ordinal-level variables Meets criteria for good measure of dispersion: 1. Use all scores in the distribution 2. Describe the average or typical deviation of the scores 3. Increase in value as the distribution of scores becomes more diverse The Standard deviation and variance are based on the distance between each score and the mean

Measure how far each number in the set is away from the mean