Inferential statistics

Question 1

normal distribution curve

Answer 1

mean, mode and median in the centre and has 50% of the scores on each side of the mean
symmetrical

Question 2

___ of all participants scores lie within one SD from the mean

Answer 2

68%

Question 3

___ of all participants scores lie within two SD from the mean

Answer 3

95%

Question 4

___ of all participants scores lie within three SD from the mean

Answer 4

99.7%

Question 5

skewed distributions

Answer 5

in normal distribution all measures of central tendency lie together in the middle of the graph. Not so in skewed distributions as there is a greater spread of scores on one side

Question 6

left skew

Answer 6

negative
mean smaller than mode

Question 7

normal distribution

Answer 7

mean, mode and median all equal

Question 8

right skew

Answer 8

positive
mean larger than mode

Question 9

probability

Answer 9

the likelihood that a certain pattern in data could be due to chance rather than the actual variables being studied

Question 10

by assessing the ______ we can determine the ______ of the results

Answer 10

probability and significance

Question 11

significance

Answer 11

a significant result is one where there is low probability that chance factors were responsible for any difference or correlation between variables tested

Question 12

parametric test

Answer 12

normally distributed data

Question 13

non parametric test

Answer 13

skewed distributions

Question 14

type 2 error

Answer 14

produced by a too strict probability
think there was no effect when there was
accept null
when incorrect
should have rejected it

Question 15

type 1 error

Answer 15

produced by a too lenient probability
think there was a significant effect when the results were due to chance
reject null
when correct
should have accepted it

Question 16

factors that effect which statistical test to use to analyze your data

Answer 16

1. distribution and spread of scores (normal,skewed)
2. research method correlation (correlation) or experiment (test of difference)
3. design of experiment, independent (unrelated), repeated/matched pairs (related)
4. level of measurement (nominal, ordinal, interval, ratio)

Question 17

when to use parametric test

Answer 17

interval data and scores must come from normally distributed spread

Question 18

observed value

Answer 18

value you calculate from your statistical test

Question 19

critical value

Answer 19

value you look up in the table that goes with the statistical test

Question 20

test rule

Answer 20

if the name of your test has a R in it then your observed value must be greater than or equal to your critical value in order to be significant