2.2.11 - quantitative data analysis

Question 1

what does central tendency tell you?

Answer 1

about the typical person in the condition/group

Question 2

what are the different ways of expressing central tendency?

Answer 2

mode, median, mean

Question 3

how do you calculate the mode?

Answer 3

count the frequency of each score in the data set - the mode is the most frequently occuring value

Question 4

how do you calculate the median?

Answer 4

put all the values in order and find the middle value

Question 5

how do you calculate the mean?

Answer 5

add all the values together and divide by the total number of values

Question 6

what does dispersion tell you?

Answer 6

how typical the central tendency is, by telling us how the data is spread out

Question 7

what are the different ways of expressing dispersion?

Answer 7

range and standard deviation

Question 8

how do you calculate the range?

Answer 8

find the difference between the largest and smallest values

Question 9

how do you calculate the standard deviation?

Answer 9

1. find the mean for the data set
2. subtract the mean from every value in the data set to give d (deviation)
3. square all the d values to get d^2 (removes negative numbers)
4. add up all the d^2 values to get ∑d^2
5. substitute the values into the formula √∑d^2/n-1 (show every step of the calculation)

Question 10

what does a smaller range or standard deviation indicate?

Answer 10

there is less variability/spread about the mean

Question 11

what should you look for when drawing conclusions from central tendency and dispersion data?

Answer 11

1. how do the typical participants differ (CT)
2. how much variability is there (D)