Module 7 - Slides Flashcards
Data Analysis / Reduction
Reduces large data sets into more compact, manageable and interpretable information
What does data analysis involve?
Organizing and Interpreting quantitative data following systematic rules, then followed by statistical analysis
Two main types of statistical analysis for quantitative data
- Descriptive statistics
- Inferential statistics
Descriptive Satistics
Used to characterize the SHAPE, CENTRAL TENDENCY, and VARIABILITY within a set of data, called a DISTRIBUTION
Parameters
Measures of population characteristics
Statistic
A descriptive index computed from sample data
Distribution
The total set of scores for a particular variable
Distribution of Scores -Coin Rotation Test (CRT)
Frequency distribution
Cumulative percent
Methods to Display Frequency Distributions
A table of rank ordered scores that shows the number of times each value occurred, or its frequency (f)
(Ex: histogram)
Graphing Frequency Distributions -Histogram
A type of bar graph, composed of a series of columns, each representing one score or group interval
Measures of Central Tendency (3Ms)
Mean (average)
Median (middle score)
Mode (the score that occurs most frequently in a distribution)
Variability
A measure of the spread of scores within a distribution, and expressed in different ways:
Range, Variance, Standard deviation (SD)
Range
From minimum to maximum
Variance
Expressed as sum of square (SS)
-Should be small if scores are close together, and large if they are spread out
Standard deviation (SD)
Square root of the variance (SS)
Normal Distribution
Known as a bell-shaped distribution or Gaussian distribution