RMA W7-9 Flashcards
What is a nominal scale?
It’s a scale where numbers are merely labels with no relationship between the size of the number and the attribute measured. It’s used for categorization, and only the mode can be used.
What is an ordinal scale?
An ordinal scale orders numbers according to the size of the attribute measured. The data is ranked or ordered, but a score of 0 is not meaningful. Only the mode and median can be used.
What are interval scales?
Interval scales have equal intervals on the scale, representing equal intervals in the property measured. They allow for negative values and can use mean, median, and mode.
What are ratio scales?
Ratio scales are similar to interval scales but have a true zero point denoting absolute absence. They do not have negative values and can use mean, median, and mode.
What is the formula for standard deviation?
It’s the square root of the sum of the squared differences between each value and the mean, divided by the number of values (N).
What is the purpose of correlation analysis?
Correlation analysis determines whether there is a linear relationship between two variables, the direction of the relationship, and the strength of the relationship.
What are the two types of correlation coefficients?
Pearson’s r is for raw scores, interval/ratio data, affected by outliers, and not suitable for skewed data. Spearman’s rs is for ranking of raw data, ordinal scale, slightly affected by outliers, and suitable for skewed data.
What are density curves?
Density curves display the overall pattern of a distribution and have an area of exactly 1 underneath them.
Where is the mean, median, mode on a density curve?
The mode is located at the peak of the density curve., median is the middle but if normal distribution than mean = median = mode
