Psy 5380 Experimental Design Quiz 1

Front 1

The probability that a sample was randomly drawn from population is measured by...

Back 1

z test and T test. (diff with t test is that you know pop mean, but not pop strd dev)

Front 2

Did incoming grad students score significantly better than the population who took the GRE?
This question is addressed by what type of test?

Back 2

z test ( 1 tailed)

Front 3

Do students in Lubbock score significantly beeter or worse than students in TX on statewide achievement tests?

Back 3

Z test

Front 4

The t distribution approaches the z distribution as...

Back 4

sample size approaches infinity

Front 5

In T Testing, for a value to be considered significant, what must be true of the critical and observed t values?

Back 5

t(observed) must be creater than t(critical) in order for something to be significant.

Front 6

In terms of p values, what must be true for siginifcance?

Back 6

For something to be signficant, p must be less than .05

Front 7

Is performance better than chance in a 5 alternative test where chance =.20? Are corrlations between predictions and performance that I find for each participant significantly greater than 0?
These questions can be adressed by using what type of test?

Back 7

t test

Front 8

What are the 3 types of t tests? Describe the differences between each type of test.

Back 8

1.single sample t test
2. dependent (paired samples) t test
3. independent (2 sample) t test

1.determines the probability that the sample was drawn from the population (or not); want to decide how likely it is that your sample is a random sample from the population
info given: pop mean, but not pop strd dev
2.-Testing whether the avg difference between two scores is zero.
-compares knowledge at begining and end of course to see if knowledge incr

3.-compares two samples to determine whether they came from the same population or not
-determines wether a difference between groups is likely/unlikely to have occured by chance
info given: 2 means, but no info about pop mean or pop std dev

Front 9

determines the probability that the sample was drawn from the population (or not); want to decide how likely it is that your sample is a random sample from the population

Back 9

single sample t test

Front 10

.-Testing whether the avg difference between two scores is zero.
-compares knowledge at begining and end of course to see if knowledge incr

Back 10

dependent (paired samples) t test

Front 11

compares two samples to determine whether they came from the same population or not
-determines wether a difference between groups is likely/unlikely to have occured by chance

Back 11

independent samples t test

Front 12

info given: 2 means, but no info about pop mean or pop std dev

Back 12

independent samples t test

Front 13

info given: pop mean, but not pop strd dev

Back 13

single sample t test

Front 14

This type of test could help you examine whether males or females do better in PSY 5380

Back 14

independent samples t test

Front 15

Was the sample selected by student 1 different from the sample selected by student 2?

Back 15

independent t test

Front 16

Is the control group mean different from the treatment group mean (is it likely that both means were drawn randomly from the same population)?

Back 16

independent t test

Front 17

Do males and females differ in their response to an advertisement?

Back 17

independent t test

Front 18

Distinguish between the 4 types of scales.

Back 18

nominal
ordinal
interval
ratio

Front 19

Classification in terns of mutually exlusive groups that do not have magnitude relationships.

Back 19

nominal scale

Front 20

breed of dog, gender

Back 20

nominal scale

Front 21

reflects differences in magnitude, but equal intervals cannot be assumed and their is no zero point

Back 21

ordinal scale

Front 22

national ranks of football teams, student's high school class rank

Back 22

ordinal scale

Front 23

reflects differences in magnitude and has equal intervals but no absolute zero point

Back 23

interval scale

Front 24

IQ scores, ACT/SAT scores, temperature scales

Back 24

interval (be/c no true zero)

Front 25

reflects magnitude, equal intervals, and has a zero point

Back 25

ratio scale

Front 26

dollars to euro conversion is reflective of which scale. Why?

Back 26

ratio scale, because equal intervals with zero pt.

Front 27

Parametric statistics are used with which scales?

Back 27

interval and ratio scalses

Front 28

nonparametric statistics are used with which scales?

Back 28

nominal and ordinal
(we don't cover in this class)

Front 29

What is the probability that a mean that large or larger would
come from a population with Mu =5.68?

Back 29

single sample t test ( in this case, 1 tailed)

Front 30

A person scored 600 on their GRE. The population mean for GRE is equal to 500, with a standard deviation of 100.
b) What percentage of the population had the same score or lower than this person?

Back 30

z score

Front 31

I have a sample with N=9 and Y bar =5.11. My population has a known mean (Mu=5.68) and a known standard deviation (sigma = 2.24).
a) What is the probability of getting a Z this low or lower?
b) What is the probability of getting a Z this high or higher?
c) What is the probability of getting a z= 0.76 or bigger and z= -0.76 or lower

Back 31

Z test

Front 32

A group of college students was randomly assigned to a lecture group or a World-Wide
Web (WWW) group. The lecture group heard a lecture on independent samples ttests.
The WWW studied the same material as presented on the Web. Then both groups were
given a test over the material. The results (percent correct on the test) were as follows:

Back 32

Independent Samples t Test ( 2 sample t test)

Front 33

. Pre- and Post-test scores for students are provided. Did the students’ performance increase significantly as a result of taking the course?

Back 33

Dependent t test (Paired Samples t Test)

Front 34

. PSY 1300 students answer questions from practice GRE at the beginning of semester.
They answer 20 questions. Each question has 5 alternatives.
a) Is the students’ performance significantly different from chance?
b) Construct a 95% confidence interval around the sample mean.

Back 34

Single sample T test

Front 35

I have a sample with a mean of 7.2 and N=9. The relevant population has a Mu = 5.68, Sj = 2.40.
a) Is my mean larger than would be expected if I had drawn my sample randomly?
b) Is my mean larger OR smaller than would be expected if I had drawn my sample randomly?

Back 35

Single sample T test

Front 36

Describe how Confidence intervals are calculated.

Back 36

lower limit: sample mean - tcritical(standard error of mean)

Upper limit: sample mean + tcrit(standard error of mean)

Front 37

Describe the central limit theorem

Back 37

If a population has a finite variance sigma squared an a mean mu, then the distribution of sample means from samples of n independent observations approaches a normal distribution with variance sigma squared/n and a mean mu as sample n increases

Front 38

Large sample sizes tell you what about the variance of the sampling distribution.

Back 38

Larger sample sizes mean less variance in the sampling distribution

Front 39

The CLT tells us what about the sampling distribution of means

Back 39

-sampling distrbution of means = population mean ( if thousands of random samples are taken)
-the sampling distribution of means will approach normality with larger samples, even if the population is not normal.