measures of central tendency and dispersion Flashcards
measures of central tendency - definition
the general term for any measure of the average value in a set of data
mean
- average
- adding up all the scores and dividing by the total number
- easily distorted by extreme value so use when there is no extreme values
what is the most sensitive measure of central tendency ?
mean
what is the most representative of data as a whole ?
mean
median
- middle value
- extreme scores do not affect it
- easy to calculate
what is the less sensitive than the mean actual values of lower and higher number are ignored ?
median
mode
- most r=frequent occurring score
- crude measure
- easy to measure
- not affected by extreme scores
what is a basic measure so it is unrepresentative ?
mode
method of dispersion - definition
measure of the spread or variation in a set of scores
standard deviation
average distance of the data from the mean of the distribution
range
- taking the lowest value from the highest value and adding 1
- does not indicate whether most numbers are closely grouped around the mean or spread out
- unrepresentative
larger standard deviation, …
the greater the dispersion or spread within a set of data
what does low standard deviation reflect ?
the fact that the data is tightly dusted around the mean
what is the precise measure of dispersion ?
standard deviation
limitation of standard deviation
can be distorted by a single extreme value
