Data Analysis: Descriptive Statistics Flashcards
1
Q
Graphs, tables and summary statistics
A
Help us identify trends and analyse sets of data.
2
Q
Measures of central tendency
A
- Mean
- Mode
- Median
3
Q
Mean
A
- Add up all the scores and divide by the total number of scores.
- The most sensitive measure of central tendency. Includes ALL scores.
4
Q
Mean evaluations
A
- includes all scores - more representative of data as whole.
- Can be distorted by extreme values.
5
Q
Median
A
- The middle value in a data set when scores are arranged highest to lowest.
- In an even number of scores the median = halfway between the two middle scores.
6
Q
Median evaluation
A
- Extreme scores don’t affect it and easy to calculate.
- Less sensitive than the mean - not all scores are included in final calculations.
7
Q
Mode
A
- Most frequently occurring score/ value
- May be more than one mode (bi-modal) or none at all.
- In some data sets = the only method you can use.
8
Q
Mode evaluation
A
- Easy to calculate.
- Crude measure. Not really representative of data as a whole.
9
Q
Measures of dispersion
A
- Based on ‘spread of scores.’
- Spread = how far scores vary and differ from one another.
- Range
- Standard deviation
10
Q
Range
A
Take the lowest value from the highest value plus 1
11
Q
Range evaluations
A
- Easy to calculate.
- Only takes into account the two most extreme values so may be unrepresentative.
12
Q
Standard deviation
A
- More sophisticated measure of dispersion.
- Tells us how far the scores deviate from the mean.
- Larger the SD the greater the dispersion or spread within a set of data.
- Large spread = not all participants were affected by the IV in the same way.
- Low SD = data is tightly clustered around the mean. All participants may have responded in a similar way.
13
Q
Standard deviation evaluation
A
- SD is more precise - includes all values.
- Can easily be distorted by a single extreme value.
