Data Analysis - Descriptive Stats Flashcards
Define descriptive statistics.
Involve summarising sets of quantitative data.
Present findings from your research in a clear and condensed form.
What do descriptive stats include?
- Measures of central tendency.
- Measures of dispersion.
- Data tables.
- Graphs and charts.
Define measures of central tendency.
They are averages.
They provide a single value which is representative of a whole set of scores by indicating the more typical value.
What are the 3 measures of central tendency?
Mode, Median, Mean.
What is the mode?
The most frequently occurring value.
What is the median?
The middle value when the scores are arranged from biggest to smallest/ smallest to biggest ( ascending/ descending).
How do you work out the median?
When there is an even number of scores in a set the 2 middle values are added together and divided by 2.
What is the mean?
The arithmetic average.
How do you work out the mean?
Adding up all of the scores in the set and dividing by the total number of scores in the set.
What are some advantages of mode?
It represents a figure that does actually occut in a set of data.
Unaffected by one or two extreme scores.
Whatvare some disadvantages of mode?
Does not tell us anything about the other values in a set of data.
Small changes in the data can radically alter the mode.
What are some advantages of median?
It remains relatively unaffected by any outlying (extreme) values.
It can be used in data with skewed distributions.
What are some disadvantages of median?
It doesn’t work well with small sets of data.
Is affected by any alteration of the central values in a set of values.
What are some advantages of mean?
Makes use of all the data in a set.
Is therefore the most powerful measure of central tendency.
What are some disadvantages of mean?
It shouldn’t he used on skewed data that has one or two outlying values - this can give a misleading average.
Inappropriate to use on ordinal and nominal data.