Ask questions
o Research questions (RQs)
Simple questions about the nature of or relationships between multiple variable
Which Presidential candidates are supported by Republicans?
Does religious orientation influence voter preferences?
o Research hypo
Reliability
Com 304
Please Open
SPSS
n Lab 7 PowerPoint
n Lab 7 SPSS File
n Variable Information Sheet
n
Preview
Attendance, Homework 6
n Reliability Statistics
n Cronbachs alpha
n
Measurement Reliability/Error
n
Measurement Reliability the degree to
whic
COM 304
Standard Scores
Todays Preview
l
Standard Normal Distribution
l
Standard (z) Scores
v
v
What qualities do they have?
v
l
What are they?
What can they be used to do?
Lecture Homework 6
Standard Normal Distribution
Standard Normal Distribution*
*Als
COM 304
Claims about Causality
Preview
l
Criteria for Establishing
Causal Relationships
l
Experiments and Causal
Claims
l
Validity of Conclusions
from Experiments
l
Lecture HW 13
Exercise cause and effect
l
A researcher brings students into the COM lab, a
COM 304
Intro to
Inferential
Statistics
Todays Preview
l Answers
to Reading 30 and 31 questions
l What are Inferential Statistics?
l Examples of how Inferential Statistics are Used
l 3 Types of Distributions
l Ways of Describing Sampling Distributions:
St
COM 304
Sampling
Distributions
Sampling Distribution Exercise: Steps
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
When each student arrives, give him/her 1 bag of M&Ms
Have each student count/record the number of green M&Ms in
his/her bag.
Have each student tell Patric
SPSS QUIZ #2 REVIEW
* Choosing the appropriate inferential statistic
A. Categorical DV vs. Categorical IV [comparison hypothesis]-> Chi-square
B. Quantitative DV vs. Categorical IV[comparison hypothesis]-> t-test
C. Quantitative DV vs. Quantitative IV[Rel
COM 304
Chi Square effect size,
results write up
Todays Preview
l Review:
what is 2?
l Effect size for 2
Cramers V
Sample results write-up
Section 51:Cramers
Why are people who live in the lap of luxury anxious?
l 1.
0 (Theyre)
l 2. no (afraid)
l 3. 100
COM 304
Correlation
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l What
are correlations?
l Interpreting scatterplots
l Four types of relationships
l Interpreting Pearson correlations
direction of effect
effect size for relationships hypotheses
l Coefficient
of Determination
What is a
COM 304
Chi Square
Todays Preview
What
is Chi Square?
One-way vs. Two-way
Steps
in computing
Steps in hypothesis testing
Exercise: what to conclude about H0
Lecture
HW 17
BB Reading: Section 50,
Computing a 2-way chi-square
answers
What proves that p
1
COM 304 Review Sheet: Final Exam (Spring 2015, Venetis)
Lecture
1. Experimental Research: what is the purpose of conducting experimental studies of communication?
What are three features of a true experiment? What are experimental (treatment) and contro
COM 304
Steps in
Hypothesis
Testing:
One sample ztest
Todays Preview
l
Brief Review: Sampling Distributions, Central Limits
Theorem, Normal Curve and Probability
l
Evaluating Research Hypotheses: the one sample
z-test (military families example)
l
Key Ter
COM 304
Confidence
Intervals for
Means
Todays Preview
Two Major Functions of Inferential Statistics:
(1)
Estimating Population Parameters:
Confidence Intervals (today)
(2)
Testing Research Hypotheses: testing
findings for statistical significance (next
we
304 exam 2
Experimental Research
What is an experiment?
The manipulation of one or more factors (independent variables) to investigate the impact on
one or more outcome variables (dependent variables)
Potential Advantages of Experiments
Allows for direct