Week 10 Flashcards
Define measures of central tedency
- Summary measure that attempts to describe a whole set of data with a single value that represents the middle of centre of its distribution
Define mean
- Sum of the value of each observation in a data divided by the number of observations
Define outliers
Observations that are distant or distinct from the other observations in a dataset
Define median
- The middle value in a distribution when values area arranged in ascending order
- Divides data in half
Define mode
- The most commonly occurring value in a distribution
Define skewness
- Measure of the asymmetry of a distribution
Describe positive and negative skew
- Positive skew, more data on the left side
- Negative skew, more data on the right side
Define leptokurtic
- When scores either side are very close together
- Resulting in sharp thin bell curve
Define platykurtic
- Flat wide bell curve
- Data are far either side
what range should skewness and kurtosis values fall
-1 and +1
Define standard deviation
- Measures of spread of the data around the mean
- Standard deviation is a measure of the average deviation of the scores from the mean
Define confidence interval
An interval of values computed from the sample, that is almost sure to cover the true population
- Confidence intervals tell you the limits within which the population mean is likely to fall
Define Z-scores
- Standardization or putting scores/ values into a form that you can use to compare across tests. These scores become known as ‘standardized’ scores
- Transform raw scores into Standardised scores
- Tells you how many standard deviations above or below the mean a score is
Define Mesokurtic
Mesokurtic: Distributions that are moderate in breadth and curves with a medium peaked height.
What are the three types of kurtosis
leptokurtic, mesokurtic, platykurtic
