Psychology 3102: Intro to Behavioral Genetics
Study Guide: Exam 1
Feb. 2014
Below is a list of people and or events
Hippocrates
BRICKS AND MORTOR
Inheritance of acquired characteristics
Aristotle
parents who have deformities have normal kids
traits after
Variability
Variability
Central tendency locates middle of distribution
How are scores distributed around that point?
Low variability vs. high variability
Ways to measure variability
Range
Interquartile range
Sum of squares
Variance
Standard deviation
Why
Central Tendency
& Scale Types
Outline
Central Tendency
Mean
Median
Mode
Scale Types
Nominal
Ordinal
Interval
Ratio
Different statistics for different variables
Central Tendency
Statistics simplify a large set of data to a single
(meaningful) numbe
Effect Size
Effect Size
If there's an effect, how big is it?
How different is from 0, or A from B, etc.?
Separate from reliability
Inferential statistics measure effect relative to standard error
Tiny effects can be reliable, with enough power
Dange
Analysis of Variance
Comparing Several Groups
Section:
M 8-10
M 12-2 T 9-11
W 8-10 R 9-11
Exam 1 Mean:
76.6%
82.5%
79.5%
83.7%
82.9%
Do the group means differ?
Naive approach
Independent-samples t-tests of all pairs
Each test doesn't use all data Less
Distributions of
Nominal Variables
Nominal Data
Some measurements are just types or categories
Favorite color, college major, political affiliation, how
you get to school, where youre from
Minimal mathematical structure, but we can still
do hypothesis
Distributions
Outline
Distributions
Frequency
Histograms
Cumulative frequency
Quantiles
Continuous variables
Shape of a distribution
Distribution
The set of values present in a sample or population
Which values occur
How often
Starting point for stati
Psychological Science I:
Statistics
Professor Matt Jones
Course Overview
Website: http:/matt.colorado.edu/teaching/stats
Approach
Conceptual understanding
Mathematical expression
Hands-on practice
Cumulative hard to recover if you get behind
Diffic
Two-sample t-tests
+14
M = 14
+14
Flood
-27
-41 M = -36.3
-41
Independent-samples t-test
Often interested in whether two groups have same mean
Experimental vs. control conditions
Comparing learning procedures, with vs. without drug, lesions, etc.
Men
Regression
Regression
Correlation can tell how to predict one variable from
another
What about multiple predictor variables?
Explaining Y using X1, X2, Xm
Income based on age, education
Memory based on pre-test, IQ
Social behavior based on personality d
Goals of Statistics
Overview
Populations and samples
Parameters vs. statistics
Types of statistics
Populations and Samples
Population
Set of subjects, items, or events we want to learn about
Generally very large or infinite
All people, all men/wome
Probability and Estimation
Probability and Statistics
Thought experiment
Know the population
Will sample n members at random
What can we say about probability of sample statistics?
p(M = x) for some value x
p(M1 > M2)
etc.
All hypothetical
Based
Hypothesis Testing
Where Am I?
Wake up after a rough night in unfamiliar surroundings
Still in Boulder?
Expected if in Boulder
(large likelihood)
Surprising but not impossible Couldnt happen IF in Boulder
(moderate likelihood)
(likelihood near zero)
Ca
Repeated-Measures ANOVA
Repeated-Measures Design
Multiple measurements for each subject
Different stimulus types, conditions, times, etc.
All measurements are of the same variable, but in different
situations
Generalizes paired-samples design
Is ther
Non-Parametric Tests
Parametric vs. Non-parametric Statistics
Parametric statistics
Most common type of inferential statistics
r, t, F
Make strong assumptions about the population
Mathematically fully described, except for a few unknown parameters
P
Three Views of
Hypothesis Testing
What are we doing?
In science, we run lots of experiments
In some cases, there's an "effect; in others there's not
Some manipulations have an impact; some don't
Some drugs work; some don't
Goal: Tell these situations
Introduction to Hypothesis Testing:
The Binomial Test
ESP
Your friend claims he can predict the future
You flip a coin 5 times, and hes right on 4
Is your friend psychic?
Two Hypotheses
Hypothesis
A theory about how the world works
Proposed as an ex
Research Design
Overview
Components of scientific studies
Types of scientific studies
Inferring causation
Independent and dependent variables
Confounds, random assignment
Quasi-independent variables
Components of Scientific Studies
Scientific study: Basi
Factorial ANOVA
Multiple Independent Variables
Simple (one-way) ANOVA tells whether groups differ
Compares levels of a single independent variable
Sometimes we have multiple IVs
Factors
Subjects divided in multiple ways
Training type & testing type
One-sample t-test
Hypothesis Test for Population Mean
Goal: Infer from M
Null hypothesis (H0): = 0
Usually 0
Sometimes another value, e.g. from larger population
Change scores
Memory improvement, weight loss, etc.
Sub-population within known, large
z-Scores
z-Scores
How good (high, low, etc.) is a given value?
How does it compare to other scores?
Today's
z-scores
Solutionsanswer:
from before:
Number
deviations
below) the mean
Compareoftostandard
mean, median,
min,above
max, (or
quartiles
Find
1
Sampling Distributions
Same Thought Experiment
Known population
Sample n members
Compute some statistic
What is probability distribution of the statistic?
Replication
Doing exactly the same experiment but with a new sample
Sampling variability means eac
Correlation
Relationships Between
Continuous Variables
Some studies measure multiple variables
Any paired-sample experiment
Training & testing performance; personality variables;
neurological measures
Continuous independent variables
How are these va