Data Analysis: Descriptive Statistics Flashcards
(7 cards)
1
Q
Descriptive statistics:
A
The use of graphs, tables and summary statistics to identify trends and analyse sets of data.
2
Q
Measures of central tendency:
A
The general term of any measure of the average value in a set of data.
3
Q
Mean:
A
- Arithmetic average calculated by adding up all the values in a set of data and dividing by the number of values there are.
- Most sensitive of the measures of central tendency as it includes all the values in the data set. More representative.
- Easily distorted by extreme values.
4
Q
Median:
A
- Central value in a set of data when values are arranged from lowest to highest.
- Extreme scores do not affect it and easy to calculate.
- Less sensitive than the mean, not all scores are included in the final calculation.
5
Q
Mode:
A
- Most frequently occuring value in a set of data.
- Very easy to calculate, very crude measure. Not really representative of the data as a whole.
- Data in categories, mode is the only method you can use.
6
Q
Range:
A
- Range is a simple calculation of the spread of scores and is worked out by taking the lowest value from the highest value and usually adding one.
- Adding 1 is a mathematical correction that allows for the fact that raw scores are often rounded up or down when they are recorded within research.
- Easy to calculate, but only takes into account the 2 most extreme values, unrepresentative of the data set as a whole.
7
Q
Standard Deviation:
A
- Measure of dispersion, how much the scores deviate from the mean by calculating the difference between the mean and each score. All the differences are added up and divided by the number of scores, variances. SD is the square root of the variance.
- Larger the SD, the greater the dispersion within a set of data. Large SD suggests that not all participants were affected by the IV in the same way, anomalous result.
- Low SD reflects the fact that the data are tightly clustered around the mean, all pps responded in a fairly similar way.
- More precise measure as it includes all values within the final calculation.