Data Flashcards
What are the Measures of Central Tendency?
Mode
Median
Mean
What is meant by Central Tendency, and Dispersion?
Central Tendency - A descriptive statistic that calculate the average almost typical value in the dataset; that is the average score recorded
Dispersion - A descriptive statistic that calculates the spread of scores in the dataset. Measures of central tendency can be misleading without knowing the variation between the scores.
What is the Mode?
Calculates The most frequent score in a data set. The mode is the value that occurs most frequently
What is the Median?
The middle number within an ordered set of values
What is the Mean?
The average number within a set of values
What type of data is the mode, median and mean typically used for?
Mode - Nominal
Median - Ordinal
Mean - Interval/Ratio Level
What are the Strengths + Weaknesses of the Mode?
The mode is very easy to determine. It is not affected by extreme scores.
However it is not a useful measure of central tendency on small data sets, with frequently occurring same values
What are the Strengths + Weaknesses of the Median?
The median is not affected by extreme scores or a skewed distribution
However, it is less sensitive than the mean and is not useful on data sets that have a small number of values, as it may not represent the typically score
What are the Strengths + Weaknesses of the Mean?
It is the most powerful measure of central tendency because all of the scores in the data set are used in the calculation
It can be affected by extreme values, or when there is a skewed distribution
What are the Measures of Dispersion?
Range
Standard Deviation
What are the Problems with the Range?
The range is affected by extreme scores, so it may not be a useful descriptive statistic if there are outliers in the dataset.
It also doesn’t tell us if the scores or bunched around the mean all more equally distributed around the mean
If the dataset has extreme scores, it is often better to calculate the interquartile range
What are the Strengths + Weaknesses of the Standard Deviation?
D
What does the Inferential Statistics Table look like?
NO IRC
Chi2, Sign, Chi2
MWU, Wilcoxon, Spearmans Rho
What does it mean by ‘Ordinal +’ ?
The levels of measurement are ranked in terms of sophistication- Nominal, then Ordinal, then Interval.
Ordinal + just means ordinal and interval data. The ones used for interval are no longer really used anymore, we just use the ordinal one for them.
What are the types of Graphical Representations of data?
Bar Graph
Pie Chart
Histogram