Review
This type of variable is also referred to as categorical
qualitative or nominal
To be 99% confident that you have not committed a Type I error, which value do you set (name / symbol) and what number do you give it?
alpha
.01
If your sample mean is 100, your population average is 90, and your standard error of the mean is 10, your observed z value is this.
-1
Which type of inferential test allows you to see if the effect of one IV depends on the level of the other IV?
two-way ANOVA (or factorial ANOVA)
The One-Way Analysis of variance can only be used to compare two groups.
True or False?
False
A subset, or part, of a population
sample
Measurement scale needed for the DV in a t-test or ANOVA?
continuous, quantitative, interval or ratio
Use this inferential test for two continuously measured variables, but not because I said so
correlation
Which type of test would you need to compare pre-test scores in intro psych with post-test scores?
repeated measures t-test
Why are you NOT allowed to say that you have proved the null hypothesis to be false?
there's always a chance of a Type I Error
Using data from a sample to make conclusions about a population
What is inferential statistics?
When you are examining the output on a two-way factorial ANOVA, you want to see if there is a Main Effect of college major on social skills. You obtain the following findings: F= 2.65, p =.067 Is there a main effect?
no
Free points
:)
If you run an ANOVA for 2 groups, you will obtain the same result as is you used this test.
independent samples t-test
With this type of statistic, high scores on one variable are associated with lower scores on the other variable
negative correlation
this type of alternative hypothesis gives equal opportunities for change
non-directional (aka, two-tailed) hypothesis
What does Cohen's d measure?
effect size
According to a recent study, the average age that an American adult leaves home is 26 years old. Assume that this variable is normally distributed with a standard deviation of 2.4 years. If a random sample of 20 adults is selected, find the probability that the mean age the participants left home is greater than 25 years old
standard error=.537
Z=-1.86
96.9%
When do you use a post hoc test? (two conditions)
1) have a significant main effect from your ANOVA
2) have at least 3 groups
Write in correct APA format: r= .60 df= 98 p=.00045
r is the statistic used for correlations
r(98) = .60, p < .001
If a researcher wants to conduct research examining the relationship between illegal drug use and violent crime, why would it be impossible for them to actually conduct an experiment?
Because it would be unethical (or impossible) to manipulate either of these variables in an experiment.
This two letter abbreviation is based on your calculations rather than a similar abbreviation that comes from being looked up
OV
A manufacturer of TV sets found that for the sets he produces, the lengths of time until the first repair can be described using a normal model with a mean of 4.5 years and a standard deviation of 1.5 years. If the manufacturer sets the warrantee so that only 10.2% of the 1st repairs are covered by the warrantee, how long should the warrantee last?
Find the zvalue that corresponds to p=.102 z=-1.27 Z=(x-µ)/ơ x=2.595 so approx. 2.6 years
MS within comes from ...
random chance, sampling error, individual variability
This part of the F ratio (term & whether it is numerator or denominator) includes the effect of the independent variable
numerator ... MS between