T-test Flashcards
Used when we have 1 IV with 2 levels
a. one-way ANOVA
b. t-test
c. two-way ANOVA
b. t-test
What does the t-test estimate?
Estimates whether the population means under the 2 levels of the IV are different
Estimates whether the population means under the 2 levels of the IV are different
a. one-way ANOVA
b. t-test
c. two-way ANOVA
b. t-test
Independent t-test is for…?
a. Between subjects
b. Within subjects
a. Between subjects
Paired t-test is for…?
a. Between subjects
b. Within subjects
b. Within subjects
Used when we have 1 IV with 2 levels, between subjects
Independent t-test
Used when we have 1 IV with 2 levels, within subjects
Paired t-test
A researcher recruited 90 dogs and their owners to take part in an agility challenge.
Before the challenge began, she told half the owners (chosen at random) that their dog showed positive signs of agility potential, and the other half that their dog did not show potential.
She then timed how long it took each dog-owner pair to complete the agility course
What are the…?
a. IVs
b. IV levels
c. DV
d. Subjects design
e. Type of test
a. Expectation of potential
b. 2 (potential, no potential)
c. Agility performance (time to complete agility course)
d. Between subjects
e. Independent t-test
What contributes to variance between IV levels in independent t-test?
List 3 things
- Manipulation of IV (treatment effects)
- Individual differences
- Experimental error; random error and constant error)
What contributes to variance within IV levels for independent t-tests?
List 2 things
- Individual differences
- Experimental error; random error)
True or False?
Manipulation of IV (treatment effects) contributes to variance between IV levels
True
True or False?
Manipulation of IV (treatment effects) contributes to variance within IV levels
False
Individual differences and experimental error (random error) contributes to variance between IV levels
What type of experimental error(s) contribute to variance between IV levels?
- Random error
- Constant error
What type of experimental error(s) contribute to variance within IV levelsfor indepdendent t-test?
- Random error
The t-distribution represents the distribution of sampled mean differences when…?
The null hypothesis is true
The t-distribution has a mean of …?
0
The extent to which an individual sampled mean difference deviates from 0 can be expressed in ______ units
Standard Error
What is the formula for differences in ESE ?
Diff. ESE = sqrt (SD a^2 + SD b^2) / (Sample size A + Sample size B)
True or False?
t is a ratio
True
t reflects the difference between ________ , expressed
in _______ units
The sample means
standard error
What can be used to determine the probability of measuring a t-value of the magnitude obtained (or greater), if the null hypothesis were true?
t-distribution
What is the formula for t
t = variance between IV levels / variance within IV levels
or
t = x difference / ESE difference
or
t = xA - xB / sqrt ((SDa^2 + SDb^2) / Na + Nb))
Is the variance between IV
levels relative to within IV levels large or small when t-value is close to 0?
Small
Is the variance between IV
levels relative to within IV levels large or small when t-value is further from 0?
Large
Small variance between IV
levels relative to within IV levels
t value is…?
a. Close to 0
b. Far from 0
a. Close to 0
Large variance between IV
levels relative to within IV levels
t value is…?
a. Close to 0
b. Far from 0
b. Far from 0
True or False?
If the null hypothesis is true, 5% of sampled t-values will fall within the 95% bounds of the t-distribution
False
If the null hypothesis is true, 95% of sampled t-values will fall within the 95% bounds of the t-distribution
True or False?
If the null hypothesis is true, 95% of sampled t-values will fall outside the 95% bounds (in the tails of the distribution)
False
If the null hypothesis is true, only 5% of sampled t-values will fall outside the 95% bounds (in the tails of the distribution)
If the magnitude of the obtained t-value is smaller than the critical value of
t, we…?
a. Fail to reject null
b. Reject null
a. Fail to reject null
If the magnitude of the obtained t-value is greater than the critical value of t, we …?
a. Fail to reject null
b. Reject null
b. Reject null
The difference between the number of measurements made and the number of
parameters estimated
sample size – no. parameters
This is known as…?
Degrees of Freedom
What is df?
The difference between the number of measurements made and the number of
parameters estimated
sample size – no. parameters