t-test: t = -/s, s is est std err, use when unknown, t greater than z to acc greater t var. H0:=#,H1:#.
t(df),p
z-test: z=(x-)/, # sd from mean, known, shape same as orig graph, z=(-)/ . H0:=#,H1:#. z,p.
sampling dist for hyp testing
indpt samp t-test: us
Chapter 7
Sampling error- the natural discrepancy, or amount of error, between a sample
statistic and its corresponding population
Distribution of sample means- collection of sample means for all of the
possible random samples of a particular size (n) t
Chapter 1- Intro to Statistics
1.1- Statistics, Science, and Observations
Statistics- a set of mathematical procedures for organizing, summarizing, and
interpreting information
o Purposes of using statistics:
1. Organize and summarize the information so
Homework #9
Due Monday 11/29/2010
For Homework #9, you will need F10 Homework #9 Dataset.sav that is also posted on Sakai under
Resources. Using this dataset, you will be conducting an ANCOVA, comparing whether different types of
music: no music, fast tem
Homework #7
Due Friday 11/5/2010
For Homework #7, you will need F10 Psyc 209 Homework #7 Dataset.sav that is also posted on
Sakai under Resources. Using this dataset, you will be conducting a t-test, comparing Optimism for
people who use Denial coping to
Homework#6
Group#1
a. TheFratioformodel1was6.298,p=.017,andtheFratioformodel2was
7.234,p=.002.Therefore,bothmodelsaresignificantlygoodfitstothedata.
b. TheRsquareformodel1was.156;therefore15.6%ofthevarianceis
accountedforbygratitude.TheRsquaredchangeformo
Graphs - histograms: picture of the frequency distribution of the data is the histogram normally distributed, positively skewed, or negatively skewed?
- boxplots (or box and whisker diagram): graphs data set and shows outliers thick black line in the mi
SPSS
Variable Types - numeric - string words asks for number of characters - make decimal 0
Label - explain the name and add more information - longer than name Discrete Missing Values - used for when you are missing data - put in a random number that
Statistics Basics, continued
- if confidence intervals DO NOT overlap then there is a statistically significant difference between the two groups even if it overlaps slightly (lower boundary of one group with upper boundary of another) then there is not
Statistics Basics Total Error = Sum of Deviances SUM(xi mean) mean = 8 Example: 10 8 8 9 5 10 8 =2 88=0 88=0 98=1 58=-3 SUM = 0 Sum of deviances is always equal to 0 Since this is not a good measure of variability, must do sum of squared errors
Sum of
Introduction
Hypothesis - always assume the null hypothesis is true until you are 95% sure there is reason to believe it is not true (p value = .05) - alternative hypothesis: generally, the opposite of the null hypothesis i.e. there was a study done that
Post hoc procedures
- useful when exploring the data - used when you have no hypotheses ahead of time - pairwise comparisons (compare all different combinations of groups) in SPSS: predictor dose outcome improvement due to medicine - must know the orde
Test Review
2 example multiple choice: 1) In a regression model with hours spent sleeping predicting mood, you find the unstandardized beta for hours spent sleeping to be 2, which indicates: for every 1 additional hour someone sleeps, their mood will be