research design power point
TRANSCRIPT
Alverno CollegeStatistics
Why learn statistics?What are the different research designs used to collect data?
Why Learn Statistics?Maybe the department has it wrong
Priorities for Part IDefinition of StatisticsPopulations vs. SampleDescriptive Statistics vs. Inferential StatisticsExperimental, Quasi-Experimental, Correlational
DesignsIndependent , Quasi-Independent, Dependent
VariablesControl vs. Experimental GroupsTypes of MeasurementStatistical Notation
What types of research questions do we ask?(Theoretical Reasoning: Analysis and Developing a Global Perspective)
What types of research questions do we ask?What types of responses are observed?
(Descriptive Statistics)
What types of research questions do we ask?What conclusions can I make about a
population based on the sample data?
(Inferential Statistics)
What types of research questions do we ask?How do groups differ from each other on a specific variable?
Comparing Groups- based on different characteristics
What types of research questions do we ask?How do groups differ from each other on a specific variable?
Comparing Groups- based on different conditions
with a rebellious peerwithout a rebellious peer
Stanley Milgram Experiments
Prisoner Guard
The Standard Prison ExperimentZimbardo
What types of research questions do we ask?Which variables help us predict specific behaviors?
(Analyze Relationships between Variables)
What do final reports of data look like?Forget what you know about study habitsImproving the Writing Skills of StudentsTexting = Epic FailThe Status of Girls in Wisconsin
A PlanTo conduct research, we need a plan!
Types of Research DesignsExperimental
Administration of condition by the researcher Cause and Effect
Quasi- Experimental Compares groups based on pre-existing
characteristics Describes Differences
Correlational Collecting Information about a specific behavior Exploring Relationships among Variables
Components of an Experimental Research Design
Independent variable: The variable the researcher will test (control).
Dependent variable: Researchers will measure responses on the dependent variable.
Components of a Quasi -Experimental Research Design
Quasi- Independent variable: The variable the researcher uses to create different groups from pre-existing characteristics.
Dependent variable:Researchers will measure responses on the
dependent variable.
Components of a Correlational Research DesignTypically we don’t distinguish between
Independent/Dependent VariablesWe examine how variables relate to each
otherNegative correlation
As one variable increases the other decreasesPositive correlation
As one variable increases the other also increases
Correlation Coefficient (Cont’d)
What is the relationship between?
Gasoline prices and grocery prices?
Stress and depression?
Depression and job productivity?
Partying and grades?
Study time and grades?
Correlation (cont’d)
Correlation coefficient “r”
0 to +.3 = weak +.4 to +.6 = medium +.7 to +1.0 = strong
0 to -.3 = weak -.4 to -.6 = medium -.7 to -1.0 = strong
-1 0 +1
DirectInverseWeak
Strong Strong
Scatterplots
Correlation between two variables plotted on graph
A diagonal line = closely related variables
Examples of Scatterplots
SAT & GPA Correlation
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0.5
1.0
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2.0
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3.0
3.5
4.0
0 200 400 600 800 1000 1200
SAT
GPA
Missed Classes & GPA
0.0
0.5
1.0
1.5
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Missed classes
GPA
Scatterplots (cont’d)
What correlation (r ) do you think this graph has?
How about this correlation?
More Scatterplots
What might this correlation be? This correlation?
Identifying Research DesignsGravetter & Wallnau 8th edition:
Page 19, learning checkPages 33-34
1, 5, 7, 9, 11, 15a & 15b, 17aIn Class Activity
Reading Published Articles Findling, et al. (2006) Gringerich & Lineweaver (2012)
HomeworkGravetter & Wallnau pages 33-346, 8, 10a, 12, 16
Experimental Design
Correlation Design
Quasi-Experimental
Research
Comparing Groups
Cause and Effect
Relationships
Having a plan
Choose the best matches
Independent Variable
Quasi-Independent Variable
Dependent Variable
Responses or Observations
Manipulated
Used to Group Participants
Choose the best matches