data analysis part 1 descriptive statistics

Question 1

what are descriptive statistics

Answer 1

analyses of quantitative data that summarise patterns saving readers from reading a lot of data to understand findings of research

Question 2

what are measures of central tendency

Answer 2

examples of descriptive data statistics that depict an overall central trend of a set of data: mean median and mode

Question 3

what is the mean

Answer 3

the sum of all numbers in the data set divided by how many numbers there are in the data set, it takes all numbers of a data set into account

Question 4

strength of mean - calculating

Answer 4

all raw data points are used in calculating the mean so it is the most sensitive measure of central tendency

Question 5

weakness of mean - distortion

Answer 5

due to its sensitivity the mean is distorted by extremely high or low values (outliers)

Question 6

what is the median

Answer 6

the middle score when the data is in numerical order, from this perspective the median may be a better descriptive statistic to report as it yields a value that is unaffected by extreme values

Question 7

median strength - central

Answer 7

central value so not affected by outliers. easy to calculate

Question 8

median weakness - sensitivity

Answer 8

does not include all values in the calculation. not sensitive. if there are all even no. data point, typical value is not a recorded value

Question 9

what is the mode

Answer 9

the most frequently occurring number in a data set, the mode can be useful by showing the most frequent value in a data set but it is of little use where the data set include many different values of the same freq

Question 10

strength - mode - discrete

Answer 10

the mode is good for discrete and categorical data as it is better to say a whole number instead of 1.89 eg as an average, it is also not distorted by outliers

Question 11

weakness mode - no and sensitivty

Answer 11

no mode if all values are different or multiple modes
not senstive due to not including all numbers in calc

Question 12

what are measures of dispersion

Answer 12

it describes the spread of data around a central value, it tells us how much variability there is in the data. there are two: range and standard deviation

Question 13

what is the range

Answer 13

where you subtract the lowest score from the highest score

Question 14

range - strength - time

Answer 14

quick and easy to calculate

Question 15

range - weakness - extreme

Answer 15

only takes into account the most extreme values and therefore is not representative of the data set as a whole

Question 16

range - weakness - indication

Answer 16

does not indicate whether most numbers are clustered around the mean or evenly spread out

Question 17

what is standard deviation

Answer 17

it calculates the spread of scores around the mean

Question 18

strength - SD - precision

Answer 18

more precise measure of dispersion because it calculates all values

Question 19

weakness - SD - calculation

Answer 19

can be distorted by extreme values and it is more difficult to calculate

Question 20

concrete example of SD

Answer 20

high SD suggests not all participants are affected by the iv in the same way. low SD is where data is tightly clustered around the mean which means most participants responded in the same way