Exam 1

Question 1

Observational research

Answer 1

• investigator measures relationships between events or conditions
• no manipulation

Question 2

experimental reserach

Answer 2

involves an investigator that directly manipulates conditions to measure a response

Question 3

reliable

Answer 3

consistent across repitions

Question 4

valid

Answer 4

obtained with sound method of measurement

Question 5

precise

Answer 5

collected values are most nearly accurate

Question 6

objective

Answer 6

data is collected by an impartial investigator

Question 7

constant

Answer 7

characteristic that can only assume one value does not need to be measured

Question 8

variable

Answer 8

any characteristic that can “vary” what is measured and typically makes up data

Question 9

discrete variable

Answer 9

limited to certain values
- e.g. whole numbers or categories

Question 10

continuous variables

Answer 10

theoretically assume any value

Question 11

nomial scale

Answer 11

mutually exclusive categories, no logical order

Question 12

ordinal scales

Answer 12

logical order, but no indication of size of difference (rank order)

Question 13

ratio scale

Answer 13

equal intervals and an aboslute zero

Question 14

interval scale

Answer 14

equal intervals but no absolute zero

Question 15

what is an absolute zero

Answer 15

indicates an instance where variables dont exist

Question 16

internal validity

Answer 16

result observed in the DV is entirely due to the treatment of the IV

Question 17

external validity

Answer 17

the result can be generalized to the wider world

Question 18

random sample

Answer 18

each member of the population has an equal chance of being selected

Question 19

stratified sample

Answer 19

ensure representation of subgroups within the population of interest

Question 20

convenience sample

Answer 20

members are selected based on “ease and proximity”

Question 21

Percintles

Answer 21

comparison to the range of scores/characteristics obtained from the larger sample or population

Question 22

what is the equation to calculate percentile

Answer 22

percentile = # of scores at and below the value/total # of scores

Question 23

what is the equation to calculate raw scores from percentiles with a frequency distribution dataset

Answer 23

(PN-C/f)i +L

Question 24

probability

Answer 24

long run proportion of a particular outcome

Question 25

trimmed means

Answer 25

mean that ignores the highest and lowest values

Question 26

geometric mean

Answer 26

restricted to positive scores (financial investments, returns, growth rate)

Question 27

harmonic mean

Answer 27

price to earning ratios in finance (also restricted to positive scores)

Question 28

equation for variance

Answer 28

V = (Sum (x-mean)^2)/(N-1)

Question 29

standard deviation

Answer 29

the square root or variance

Question 30

coefficient of variation

Answer 30

CoV = SDx/mean * 100

Question 31

when to use coefficient variation

Answer 31

when there are two datasets are different in magnitudes to compare to each other

Question 32

Z-scores

Answer 32

- used to figure out how far away a piece of data is from the rest of the group - express the raw score in SD units

Question 33

what is the quation for Z scores

Answer 33

Z = x - mean/SDw

Question 34

T scores

Answer 34

used to compare a sample population mean to the mean of the population. esp when sample pop is small or SD is not there - only can be used on normally distributed data

Question 35

equation for T scores

Answer 35

T = 10Z + 50

Question 36

positive skew

Answer 36

the tail is in the positive direction

Question 37

no skewness

Answer 37

a normal distributoin

Question 38

negative skewness

Answer 38

the tail is in the negative direction

Question 39

what is the equation for skewness

Answer 39

S = sum Z^2/N then divide by SEs = sqrt (6/N)

Question 40

kurtosis

Answer 40

the steepness of a distribution

Question 41

platykurtic

Answer 41

wide range of scores, low concentration around mean - k<0

Question 42

leptokurtic

Answer 42

narrow range of scores high concentration around mean - K > 0

Question 43

mesokurtic

Answer 43

moderate range, moderate concentration

Question 44

what is the equation for kurtosis

Answer 44

K = (sumZ^4/N) - 3.0 then difvide by SEk = sqrt (24/N)