Statistics

Question 1

when is the median used?

Answer 1

ranked or skewed data

Question 2

when is the mean used?

Answer 2

interval level data

Question 3

how to calculate variance

Answer 3

square the arrows, add squares, divide by total number of arrows

Question 4

standard deviation

Answer 4

take sq root of variance figure

Question 5

what is variance used for?

Answer 5

to tell us what the spread of the data is

Question 6

what is the standard deviation?

Answer 6

a measure of the spread of the data

Question 7

measures of central tendency

Answer 7

mean, median, mode

Question 8

in giving descriptives, what should we report?

Answer 8

the mean and the standard deviation

Question 9

what does the standard deviation show?

Answer 9

the variance within the data

Question 10

what is the null hypothesis

Answer 10

a statement that there is no effect

Question 11

what is the significance?

Answer 11

the chance of finding effect

Question 12

what is a statistical effect for?

Answer 12

it tells us the probability that an effect occurred by chance

Question 13

what significance level should we look for?

Answer 13

.05

Question 14

what is a test distribution?

Answer 14

the distribution of the scores, most fall in the centre 95%, with 2.5% either side (bell curve shape)

Question 15

what is a critical value?

Answer 15

the value a test must reach for significance (the number you compare your ‘absolute value’ to)

Question 16

if a result is p < .05 is this significant?

Answer 16

yes

Question 17

what is the p value?

Answer 17

the measure of probability that the hypothesis being correct was chance (you want it to be below .05 to be significant - 5%)

Question 18

if p < .001 what does this mean?

Answer 18

that it was very significant

Question 19

if p > 0.05 what does this mean?

Answer 19

it was not significant

Question 20

what are degrees of freedom?

Answer 20

the number of values that are free to vary

Question 21

what is the most common constraint giving N-1?

Answer 21

the mean of the scores (as this is fixed)

Question 22

are degrees of value better in small or large samples?

Answer 22

in small they’re better, because in large the critical values are usually similar

Question 23

the higher the df, the lower the…

Answer 23

critical values are.

because you tend to have more people, (so N-1 is higher) so it’s easier to find affect and reach significance because there is more data

Question 24

the smaller the p value, the higher the…

Answer 24

critical values are.

more significant; therefore values are higher to reach.