Descriptive statistics Flashcards
Measures of central tendency definition?
the relationship of the values with the central point
Least to most precise/ sensitive MOCT
mode -> median -> mean
how to calculate mean ?
= the average
add up all numbers/ number of numbers
how to calculate mode?
= most common number, may be more than 1
putting similar scores together, and counting which appears most frequently
median calculate?
= central value
- arranging scores in order and finding mid point
advantages of the mean?
+ appropriate to use for further statistical analysis such as standard deviation
+ appropriate to use for ordinal, interval, ratio levels of data
mean disadvantages?
- affected by extreme scores so can misrepresent no.s
- may produce a value that no ppt in the data set achieved
mode advantages?
+ unaffected by extreme scores
+ can be used with nominal (categorical data) & provides info abt freq
+ unlike mean and median, there is always a modal score
mode disadvantages?
- ignores values by only looking at the freq of no.s, this may lead to biased representation as an outlier score may be the most frequent
- can be unclear as data may have several modes - bimodal = 2
median advantages?
+ makes use of all the values but is not as biased by extreme scores as mean
+ can be used with ordinal data
median disadvantages?
- more open to bias from extreme scores than mode
- unhelpful for further statistical analysis such as standard deviation
what is measures of dispersion?
how dispersed or spread out the data are
range calculated?
the range is a measure the spread of a set of scores, shown by the difference between highest and lowest
standard deviation?
measure of the spread of data around th mean.
higher value = more variation in your scores
range +?
+ easier to calc than standard deviation
+ takes into account extreme values