University:
York University
Course:
PSYC 2021 | Statistical Methods I
Academic year:

2024
Views:

443

Pages:

3
Author:

Nick T.

Lab 2 Samples and Population • Population - the entire set of items/people of interest • rarely (if ever) have information on each member of a population - Sample the part of the population used for Study use the sample to infer characteristics of the population Population notation - mean = N Variance = 0 - Standard deviation: 0 Sample notation mean = X Variance S (SD) Standard deviation: s (SD) Central Tendency mean the average of a group of scores Sum the Scores; divide by the total number of scores (N) - X = ΣΧ/Ν ↳ X = mean ↳ E = Sum together ↳ X = Scores in distribution ↳ N= number of scores in the distribution • median - the middle value in in a group of scores (ranked lowest to highest) - with an even number of scores, there will be two values in the middle. the median will be the average of these two numbers • find the median - arrange Scores from lowest to highest - Find middle score by adding o the number of scores (N) and dividing by I to 2 - Count to the middle score or scores • mode - the value that occurs most in a group of scores in a distribution, the mode will be at the peck, indicating the vawe occurs the most frequently SPSS Basics • Create variables and enter data -IBM SPSS Statistics Variable view... is where we create varioubles • data view... is where we enter data 26 individuals were interviewed for a study on fitness; each person reported the number of years they have had a gym membership - N=26 - x = years of gym membership • 16,0,5,10,19,0,2,8, 11, 3, 15, 10,17,9,6,12,7,9, 15, 11,9, 11, 12, 19,0,10 • frequency taldes - analyze descriptive Statistics frequencies move variable to the 'Varicude (s) box - 'OK' histograms - analyze descriptive statistics frequencies - move variable to the variable(s) box - Click 'Charts' 'histograms' - 'OK' Standard Deviation • Standard deviation: how much each score varies from the mean (on average) • how to calculate Standard deviation given some data: 1) Calculate mean 2) Calculate sum of Squares 3) Calculate variance -4) Square root variance to get Standard deviation Variance • Variance: measure of how spread out the scores of a distribution are narrow, less spread out distribution = less variance wider, more Spread out distribution = more variance • distributions are "norma" when bell Shaped and Symmetrical