Zusammenfassung der Ressource
Research Results
- Frequency distributions
- Indicates the number of
participants who receive
a score on a variable
- Pie chart
- Bar graph
- Used to compare group
means or percentages
- Frequency polygons
- Uses a line to
represent frequencies
- Used in interval or ratio scales
- Histograms
- Uses bars to display a frequency
distribution for a quantitative variable
- Descriptive statistics
- Central tendency
- Mean
- X bar or M
- Median
- mdn
- Mode
- Good for nominal scales
- Tells us what the sample
as a whole is like
- Variability
- Characterizes the amount of
spread in a distribution of scores
- Standard deviation
- The average deviation
of scores from the mean
- Variance
- The standard deviation
is derived from this
- Range
- Correlation coefficients
- Statistic that describes how
strongly variables are related
- Pearson product moment
correlation coefficient
- Used when both variables
have interval or ratio scale
properties
- Provides information about
strength and direction
- Restriction of range
- When individuals in
sample are similar
- Can only find linear relationships
- Effect size
- Strength of association
between variables
- Squared correlation coefficient
- The percent of shared variance
between two variables
- Correlation = .7, therefore % = 49%
- Cohen's D
- The magnitude of the effect
of the independent variable
on the dependent variable
- Regression equations
- Used to predict one's score
when that person's score on
another test is known
- Multiple correlation
- Combines predictor
variables to increase the
accuracy of a prediction
- Partial correlation
- Provides a way of
statistically controlling third
variables in non experiments