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Distributions
How do we describe a distribution?
Lesson 5: z-scores
Normal Distributions
Normal distributions are precisely defined
and always the same shape
1. Shape (symmetrical, +/- skewed
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Central Tendency
Goal of Descriptive Statistics
Lesson 3:
Central Tendency
To organize and summarize large groups of
data
We want a handful of numbers that
summarize a lot of numbers*
Measu
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Lesson 6: Probability
In inferential stats, we never deal in certainty
because of sampling error.
Probability is a method for measuring and
quantifying the likelihood of obtaining a specific
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Distribution of Sampling Means
Lesson 7:
SAMPLING DISTRIBUTION
The Distribution of Sample Means
The distribution of the means from all
possible random samples of a given size
Distribution o
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Variability
Lesson 4: Variability
A measure of how spread out the scores
are in a distribution.
Accompanies central tendency as basic
descriptive statistic
Variability
Central Tendency and V
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Psychology
Lecture 1:
Introduc.on to Sta.s.cs
No simple answers
Mul.ple Causes
Scien.c Study of
Aect: Feelings
Behavior: Observable; what people do
Cogni.o
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Lesson 2:
Frequency Distributions
We can describe any data set with three
pieces of information:
1. Shape of the distribution
2. Central tendency
3. Variability
Distributions tell us:
Every
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Hypothesis Testing
Lesson 8:
Introduction to
Hypothesis Testing
Goal: to rule out chance (sampling error)
as a plausible explanation for results.
Hypothesis testing helps determine
whether a