statistics

Question 1

mode

Answer 1

• value(s) that appear the most no. times in data set
• adv: isn’t too affected by anamolous results & quick/ easy to calulate
• dis: can be more than one modal value so may not give a definitive answer & doesn’t take account all values

Question 2

mean

Answer 2

• scientific averahe that’s calculated by adding all values together & dividing total by no. values in data set
• adv: takes all values into account so more rep of whole data set
• dis: skewed by anamolous results & more time consuming to calculate

Question 3

median

Answer 3

• order values in rank order & if data set has odd no. values, just find middle no. BUT if even no. values add two middle no. together & divide total by two
• adv: isn’t too affected by anamolous results & can be quite quick/easy 2 calculate
• dis: doesn’t take all no. in data set into account & can be more complicated if there’s 2 middle no.

Question 4

range

Answer 4

• difference between largest & smallest value in data set
• adv: simple/quick 2 calculate (& can be used 4 ordinal)
• dis: if extremes are anamolies then could negatively skew result & doesn’t take all values into account

Question 5

standard deviation

Answer 5

• spread of values about the mean
• adv: most scientific, takes all values into account, most accurate M.D for mean, can be used to assess significance & less affected by anamolies
• dis: takes a long time to work out as involves many steps & uses all values & assumes normal distribution pattern

Question 6

chi squared

Answer 6

• difference, nominal data, independent groups

* significant if observed is GREATER than critical

Question 7

sign test

Answer 7

• difference, nominal data, repeated measures (& matched pairs ??)
• significant if observed is LESS than critical

Question 8

wilcoxon

Answer 8

• difference, ordinal data & above, repeated measures

* significant if observed is LESS than critical

Question 9

mann whitney u

Answer 9

• difference, ordinal data & above, independent measures & matched pairs
• significant if observed is LESS than critical

Question 10

spearman’s rank

Answer 10

• relationship, ordinal data & above, repeated measures

* significant if observed is GREATER than critical

Question 11

nominal

Answer 11

• categorical data, represented by bar charts & lowest level
• adv: easy to generate from closed questions & can quickly collect lots of detail
• dis: can only calculate mode & without linear scale, may not be able to identify diff degrees of a response

Question 12

ordinal

Answer 12

• data is ranked (may be measured on a scale) & don’t know gaps between each values & may not be equal
• adv: provides comparable values on linear scale (so more info than nominal)
• dis: don’t know gap between each value so can’t be used to calculate mean

Question 13

interval

Answer 13

• no true zero, equal inclines between each value, continuos data & rep by histogram/line graph
• adv: can be used to calculate mean & equal inclines means values can be directly compared
• dis: no baseline if scientific method isn’t used & ps may not demonstrate a value that can be measured on scale

Question 14

ratio

Answer 14

• true zero, equal inclines, continous data, rep by histogram/line & highest data level
• adv: can be used to calculate mean & values can be directly compared
• dis: doesn’t provide a lot of detail or reasoning