02 Basics of Statistics Vocab

Question 1

variation due to the experimenter doing something to all the participants in one condition and not in the other condition

Answer 1

systematic variation

Question 2

variation that results from random factors that exist between the experimental conditions

Answer 2

unsystematic variation

Question 3

all data is distributed symmetrically around the center of all scores

bell curve

Answer 3

normal distribution

Question 4

lack of symmetry

Answer 4

skew

Question 5

tail points toward higher or more positive scores

Answer 5

positive skew

Question 6

tail points toward lower or more negative scores

Answer 6

negative skew

Question 7

degree to which scores cluster at the ends of the distribution (tails) and how pointy a distribution is

Answer 7

kurtosis

Question 8

many scores in the tails and is pointy

Answer 8

positive kurtosis

Question 9

few scores in the tails and tends to be flatter than normal

Answer 9

negative kurtosis

Question 10

score in the data set which occurs most frequently

Answer 10

mode

Question 11

middle score when the data is ranked in order of magnitude

Answer 11

median

Question 12

average score of data set

Answer 12

mean

Question 13

average of a population

Answer 13

µ

Question 14

average of a sample

Answer 14

x-bar

Question 15

largest score » smallest score

Answer 15

range

Question 16

range which excludes values at the extremes of the distribution

Answer 16

inter-quartile range

Question 17

3 scores that split the sorted data into 4 equal parts

Answer 17

quartiles

Question 18

median of the upper half of the data set

Answer 18

upper quartile

Question 19

median of the lower half of the data

Answer 19

lower quartile

Question 20

allow researchers to calculate the probability that a score will occur when the data is normally distributed

Answer 20

z-scores

Question 21

determines whether the alternative hypothesis is likely to be true

Answer 21

interferential statistics

Question 22

probability that the result is a chance finding

Answer 22

p-values

Question 23

SS

Answer 23

sum of squared errors

Question 24

s2

Answer 24

variance

Question 25

s

Answer 25

standard deviation

Question 26

difference between the observed data and the model of the mean

Answer 26

deviance

Question 27

square the difference between observed score and mean value

Answer 27

sum of squared errors (SS)

Question 28

average error between the mean and observed scores

Answer 28

variance (s2)

Question 29

square root of variance

Answer 29

standard deviation (s)

Question 30

samples from the same population will vary slightly because they contain different members of the population

Answer 30

sampling variation

Question 31

frequency distribution of the sample means from the population

Answer 31

sampling distribution

Question 32

standard deviation of the sample means

Answer 32

standard error of the mean

Question 33

√(standard error of the mean)

Answer 33

standard error

Question 34

as samples get large, the sampling distribution has a normal distribution with a mean equal to the population mean

Answer 34

central limit theorem

Question 35

CI

Answer 35

confidence interval

Question 36

provides another approach to assess the accuracy of the sample mean as an estimate of the population mean

Answer 36

confidence interval

Question 37

sample mean must be vary close to the true mean

Answer 37

small CI

Question 38

sample mean is not similar to the true mean and thus is a bad representation of the population

Answer 38

wide CI

Question 39

one-tailed test

Answer 39

directional hypothesis

Question 40

two-tailed test

Answer 40

non-directional hypothesis

Question 41

1-beta =

Answer 41

power

Question 42

free program that can be downloaded to determine sample size to achieve a desired level of power

Answer 42

G*power