Paper 1 - Data/statistics

Question 1

what are measures of central tendency ?

Answer 1

averages of the data
mean, median and mode.

Question 2

what are the advantages and disadvantages of mean ?

Answer 2

it is affected by outliers.
it uses every value in the data, so represents the data well.

Question 3

what are the advantages and disadvantages of median ?

Answer 3

less effected by outliers.
does not account for the distance between values.

Question 4

what are the advantages and disadvantages and mode ?

Answer 4

can be used for nominal and ordinal data.
when there is more than one mode it does not reflect the centre of data well.

Question 5

what are measures of dispersion ?

Answer 5

the spread of data
range, variance and standard deviation

Question 6

what are the advantages and disadvantages of range ?

Answer 6

• easy to calculate
• effected by extreme values

Question 7

what is variance ?

Answer 7

measurement of the spread between numbers in a data set.
standard deviation squared

Question 8

what is standard deviation

Answer 8

the square root of variance
how dispersed the data is from the mean

Question 9

what are the advantages and disadvantages of variance and standard deviation

Answer 9

• all values are taken into account
• complex to calculate

Question 10

what do bar charts represent ?

Answer 10

nominal data

Question 11

what do histograms represent ?

Answer 11

continuous data

Question 12

what to line graphs represent ?

Answer 12

continuous data

Question 13

what do pie charts represent ?

Answer 13

nominal data

Question 14

what do scatter graphs represent

Answer 14

correlational data

Question 15

what does ∝ mean

Answer 15

proportional to

Question 16

what are inferential statistics ?

Answer 16

procedures for drawing logical conclusions about the target population that the sample was drawn from.

Question 17

what’s the observed value ?

Answer 17

the value produces after applying an inferential test formula.

Question 18

what’s probability ?

Answer 18

the measure of the likelihood that an event may occur.

Question 19

what is the significance level ?

Answer 19

the level of probability at which it has been agreed to reject the null hypothesis. 0.05.

Question 20

what’s a type one error ?

Answer 20

when the researcher rejects the null hypothesis that is true.

Question 21

what’s a type two error ?

Answer 21

when the researcher accepts a null hypothesis which is not true.

Question 22

What’s quantitative data and its advantages/disadvantages ?

Answer 22

Data in numbers.
-Its easier to analyse because data is numerical which can be summarised using descriptive statistics (averages and graphs). This makes it easier to draw conclusions from the study as the data is represented clearly.
-It oversimplifies reality and human experience as it suggests that there are simple answers.

Question 23

What’s qualitative data and its advantages/disadvantages ?

Answer 23

Non numerical data, e.g. pictures or words.
-Represents the true complexities of human behaviour because they’re not reduces to numbers.
-Provides rich detail of how people think and behave. This increases validity.
-More difficult to detect patterns and draw conclusions from because of the large variety of information collected.

Question 24

What are the 3 levels of data and what do they mean ?

Answer 24

nominal- categories
ordinal - ranked
interval - public units of measurements

Question 25

what does a small standard deviation mean ?

Answer 25

scores are close to the mean

Question 26

what does a large standard deviation mean ?

Answer 26

scored are far from the mean - lots of individual differences

Question 27

What are the steps for the wilcoxon test ?

Answer 27

1. calculate the difference between each pair of scores. if the difference is zero ignore it in ranking.
2. rank the differences from low to high ignoring negatives.
3. add up the ranks for positive differences. then for the negative differences.
4. chose the smallest value (observed value).
5. compare it to the critical value table and write the significance statement.

Question 28

in the wilcoxon test, does the observed value need to be lower or higher than the critical value ?

Answer 28

equal to or lower than.