Textbook Notes (368,317)
Canada (161,798)
Psychology (3,337)
PSYC 1010 (57)
c (11)
Chapter 6

Chapter 6.docx

3 Pages
119 Views
Unlock Document

Department
Psychology
Course
PSYC 1010
Professor
c
Semester
Fall

Description
Chapter 6- Normal curve, Standardization, z Scores Feb. 11th Normal Curve - Specific bell-shaped curve that is unimodal, symmetric and defined mathematically - Describes the distributions of many characteristics and measures that vary - A distribution resembles a normal curve as the size of the sample approaches the size of the population (if the population is normally distributed) Standardization - Converts individual scores to standard scores for which we know the percentiles (if data is normally distributed) - Converts individual scores from different normal distributions to a shared normal distribution with a known mean, standard deviation and percentiles Z-Scores - The number of standard deviations a particular score is from the mean - Give us the ability to convert any variable to a standard distribution, allowing us to make comparisons among variables - Any score using any measure can be converted to a z distribution (ex. height and weight can be compared using z scores) - Create an oppurtunity to make meaningful comparisons by putting different variables on a common scale 1) Z scores give us a sense of where a score falls in relation to the mean of its population 2) Z scores allow us to compare scores from different distributions 3) Z scores can be transformed into percentiles - Transforming Raw Scores into z Scores:  We need the mean and standard deviation of the population of interest in order to convert a raw score into a z score  Z distribution always has a mean of 0 (if you are exactly at the mean than you are 0 standard deviations from the mean)  Z distribution always has a standard deviation of 1 - Steps in calculating z scores :  Determine the distance of a particular score from the population mean- X-  Express this distance in terms of standard deviations- z= (divide the distance by the standard deviation of the population) - Transforming z Scores into Raw Scores  If we already know the z score, we can reverse our calculations to determine the raw score - Steps in calculating raw score from z score  Mulatiply the z score by the standard deviation of the population  Add the mean of the population to this product  Converting z Scores to Percentiles - Normal curve allows us to convert scores to percentiles- 100% of the population is represented under the bell-shaped curve - The midpoint in a normal curve is the 50th percentile - Z distribution- a normal distribution of standardized scores - Standard normal distribution- a normal distribtion of z scores - The standardized z distribution allows us to : 1) Transform raw scores into standardized scores called z scores 2) Transform z scores back into raw scores 3) Compare z scores to each other- even when the z scores represent raw scores on different scales 4) Transform z scores into percentiles that are more easily
More Less

Related notes for PSYC 1010

Log In


OR

Join OneClass

Access over 10 million pages of study
documents for 1.3 million courses.

Sign up

Join to view


OR

By registering, I agree to the Terms and Privacy Policies
Already have an account?
Just a few more details

So we can recommend you notes for your school.

Reset Password

Please enter below the email address you registered with and we will send you a link to reset your password.

Add your courses

Get notes from the top students in your class.


Submit