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descriptive statistics - Coggle Diagram
descriptive statistics
measures of central tendency (what the relationship is of the values with the central point)
mean= the average
+appropriate to use for further statistical analysis such as a standard deviation
+appropriate to use for ordinal, interval and ratio levels of data
-it is affected by extreme scores (high or low) and can misrepresent the numbers as a result
-may produce a value that no participant in the data set achieved
to calculate this you add up all numbers in a data set and then divide this by the number or numbers
mode= the most common number
-it ignores values by only looking at the frequency of numbers, this may lead to a biased representation as an outlier score may be the most frequent
-can be unclear as the data may have several modes (bi-modal= 2 modes)
this is calculated by counting which score occurs the most and can generate more than one modal score if there are the same number of scores for two or more numbers
+unaffected by extreme scores
+it can be used with nominal (categorical) data, and that it provides information about frequency
+unlike the mean and median there is always a modal score
median= central value
+makes use of all the values but is not as biased by extreme scores as using the mean
+it can be used with ordinal data
-more open to bias from extreme scores than the mode -unhelpful for further statistical analysis such as using standard deviation
this is calculated by arranging scores in order and finding the mid point
measures of dispersion (how dispersed or spread out the data are)
range
the range is a measure of the spread of scores, shown by the difference between the highest value and the lowest
+its easier to calculate than standard deviation +takes into account extreme values
-it is affected by extreme values -it does not give info on whether the scores are clustered around the mean or spread out
standard deviation
+it gives a more precise and informative measure of dispersion than the range, as it does not just take into account the highest and lowest scores
+less affected by anomalous results than range scores as extreme scores are ignores
-it is more complicated to calculate than the range -can only be used when the data set is normally distributed and not skewed
this is the measure of the spread of data around the mean. the higher the value the more variation in your scores