Statistics

Question 1

Bell Curve

Answer 1

Normal distributions with mean of 100. 34.1% to right of middle and 34.1% to left of middle average

Question 2

Mean

Answer 2

Average

Question 3

Mode

Answer 3

that occurs the most

Question 4

Median

Answer 4

Middle #

Question 5

Negative skew

Answer 5

tail is on the left

Question 6

Positive skew

Answer 6

tail is on the right

Question 7

What is central tendency

Answer 7

tendency of scores to cluster around some central value

Question 8

If test scores are positively skewed how would one create a better symmetrical distribution

Answer 8

by deleting tough questions and substituting them with easier ones

Question 9

Standard Error of Measurement

Answer 9

how much difference to expect from one sample to another (same as confidence interval) repeated measures on same instrument distributed around true score

Question 10

Standard Deviation

Answer 10

deviation from the mean. SD of 100 it is 15 points above or below for 1 SD

Question 11

4 ways for test interpretaion

Answer 11

Standard Score-mean of 100; Scaled Score-raw score translated into comparable score, Mean of 10 SD of 3, T score, Percentile Rank

Question 12

What is a T-score

Answer 12

normal distribution-likelihood of observations-how does data compare to what is expected. Mean of 50 and SD =10

Question 13

Z score

Answer 13

how many SD a data point is from the mean in a normal distribution. ranges from -3 SD to +3 SD-way to compare results to a normal population

Question 14

Effect Size

Answer 14

measurement of absolute magnitude. helps determine if the difference is real or due to change factors. strength of relationships between two variables

Question 15

Dependent Variable

Answer 15

variable being observed and measured-event expected to change when independent variable is manipulated

Question 16

Independent Variable

Answer 16

variable that is changed or manipulated

Question 17

Type 1 error

Answer 17

said there was an effect by wasn’t one. rejecting null hypothesis when it was actually true (False Positive)

Question 18

Type 2 error

Answer 18

There was an effect and you missed it-failing to reject the null hypothesis (False Negative)

Question 19

Null hypothesis

Answer 19

there is no significant difference

Question 20

Pearson Correlation Coefficient (r)

Answer 20

measure correlation varies b/w -1 and +1 effect size . effect size is low if value of r is around .1, medium if r varies around .3 and large if r varies more than .5

Question 21

Regression

Answer 21

used to measure predictions-determine the strength and character of relationships between one dependent variable (Y) and a series of other independent variable

Question 22

Cohen’s D

Answer 22

Used to measure effect size when you’re comparing a treatment to a control group