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LGAF 6204 - Research Methods
Final Exam
44
Mathematics
Graduate
06/23/2013

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Cards

Term
Inferential Statistics
Definition
Go beyond the sample to estimate, generalize to the population.
Term
Steps for Hypothesis Testing
Definition

1. Identify the Research Hypothesis

2. Identify the Null Hypothesis

3. Assume the Null Hypothesis to derive a sampling distribution

4. Determine the Critical Region

5. Calculate the Sample Statistic for our sample

6. Make A Decision

7. Determine Chance of Error

 

Term
Type 1 error (primary)
Definition
Rejecting a true null hypothesis
Term
Type 2 error (beta)
Definition
Failure to reject a false null hypothesis
Term
Research hypothesis
Definition
What we want to infer about the general population. It cannot be tested directly because we only have a sample.  Might include direction eg. "positive correlation".
Term
Null hypothesis
Definition
Opposite of the research hypothesis.  A hypothesis that assumes there is no correlation (or negative correlation in some cases) between the variables. It is used to derive a sampling distribution to compare with the research hypothesis. It may be univariate and gives a fixed value.
Term
Sampling distribution
Definition
A mathematical theoretical probability distribution based on what we expect to happen if the null hypothesis is true and we drew an infinite number of samples.
Term
Critical region
Definition
Region of rejection. Extreme events that are so improbable under the null hypothesis that we reject it and infer the research hypothesis.
Term
Level of significance
Definition
The chance of making a type-1 error. Also called a probability value or p-value. It should be less than 5%.
Term
One tailed test
Definition
The critical region lies on only one tail of the standard normal curve and the hypothesis specifies a direction.
Term
Two tailed test
Definition
The critical region lies on the left and right hand tails of a normal curve.
Term
Confidence level
Definition
A range identifying the probability that the sample statistic in the research hypothesis matches the population parameter. It is measured in units of standard error (z scores) or percentages and is usually set at 95%. This means that we are 95% confident we have captured the true population value in the interval.
Term
Explain what happens to a sampling distribution as sample size increases and why this occurs
Definition
As the sampling size increases, the sampling distribution becomes more accurate because we have a better estimate of the population parameter. We are less likely to get extreme outcomes if the null hypothesis is true
Term
What is meant by "proportional reduction in error?"
Definition
Proportional reduction in error _ how much better can we estimate the dependent variable (Y) using the independent variable (X) than estimating the dependent variable by itself?
Term
Measures of bivariate association
Definition
Lamda, Gamma, R and R2 (tau?)
Term
Lamda - Level of Measurement
Definition
2 Nominal or 1 Nominal and 1 Ordinal; Lamda is a PRE
Term
Lamda Variance
Definition

Variance = 0 (<) Lamda (<) 1.00

 

Lambda falls between 0 and 1
Term
Lamda Problems
Definition
When mode lands in one row of dependent variable, Lamda will equal 0
Term
Gamma - Level of Measurement
Definition

2 Ordinal Variables; Measure of how much better we can estimate the order on the dependent variable knowing the order of the independent variable. Gamma is a PRE

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Term
Gamma Variance
Definition

-1 < Gamma < 1

Gamma falls between -1 and 1

 

Term
Gamma Assumptions
Definition
Assumes that high values in dependent variables will coincide with high values in independent variables and vice versa or lows with highs and vice versa
Term
Gamma Problems
Definition
Gamma fails to take ties into account, which inflates the correlation. Therefore Tau is used to take tied values into account (Tau is not a PRE).
Term
Tau
Definition
Tau corrects Gamma by including ties in the calculation. Tau is not a PRE and requires two ordinal variables. Absolute value of tau is always less than or equal to the absolute value of gamma.
Term
R and R 2 - Level of Measurement
Definition
Level of Measurement: Interval / Ratio;  Use Ordinary Least Square Regression (OLS). R is not a PRE.  R2 is a PRE
Term
R & R2 Variance
Definition
R falls between -1 and +1; R2 is between 0 and 1; r gives the magnitude and the direction of the relationship.  ASSUMES LINEAR RELATIONSHIP
Term
R and R2 Assumptions
Definition
R and R2 assume a linear relationship between the variables
Term
What is meant by elaboration and control
Definition
Very few relationships are bivariate in nature so we use other variables (third, fourth, etc) to further explain (elaborate) and control the relationship between the dependent and independent variable.
Term
What 3 factors are appropriate to consider in control and elaboration?
Definition

1-Demographics

2-Time and Place

3-Interest and Concern

Term
Why use elaboration and control (multivariate)? (2 reasons)
Definition

a) to test for spuriousness

b) to elaborate on the relationship b/t x&y.

Term

What can happen to the correlation when we add z? (3 things)

Definition

a) nothing - z has no effect

b) correlation reduces drastically which means either the realtionship between x&y is spurious or z is an intervening variable

c) The correlation b/w x&y changes but does not disappear therefore z is a conditional variable

Term
Discuss the 4 major issues in questionnaire construction
Definition
1-Content
2-Close vs Open Ended Questions
3-Response Format
4-Question Sequence
Term
What 8 things should you consider when you evaluate a poll
Definition
1-Topic
2-Question Wording
3-Question Order
4-Sample Definition
5-Sub-group size
6-Error margins
7-Poll sponsor
8-What's the spin?
Term
Advantages to Interviewer Administered Survey Methodology (3)
Definition
1-Higher response rate
2-Flexibility to probe/clarify
3-Quick results
Term
Disadvantages to Interviewer Administered Survey Methodology (3)
Definition
1-High cost
2-Interviewer bias
3-Lack of anonymity
Term
Advantages to Respondent Administered Survey Methodology (4)
Definition
1-Less expensive
2-No interviewer bias
3-Considered responses
4-Greater anonymity
Term
Disadvantages to Respondent Administered Survey Methodology (4)
Definition
1-Low response rate
2-No one to probe/clarify
3-Takes time to get results
4-No control over who responds
Term
Advantages of Secondary analysis (3)
Definition
1-Cost
2-May be the only source
3-Replicate results of primary data for accuracy
Term
Disdvantages of Secondary analysis (3)
Definition
1-May only approximate data you want
2-May be biases you're unaware of
3-May be difficult to get access to data
Term
Focus Group methodology
Definition
small groups (6 - 8 people) that evaluate something. It has advantages and disadvantages over public opinion surveys
Term
Focus Group methodology Advantages (5)
Definition
1-Less expensive
2-Less prep time needed
3-No need to construct a survey
4-May not ask the appropriate questions on a survey (sort of fixed-in to set)
5-In-depth information
Term
Focus Group methodology Disadvantages (4)
Definition
1-No external validity
2-Product is open to interpretation
3-May have moderator biases
4-Demand characteristics (do people behave differently)
Term
Two Major issues of ethics in conducting research
Definition
Informed Consent and Right to Privacy
Term
Ethics-Informed consent 3 issues
Definition

1-They must be competent to make a decision (COMPETENT)

2-They must have full comprehension of the risks involved (COMPREHENSION)

3-The decision to participate must be voluntary (VOLUNTARY)

Term
Ethics-Right to privacy 5 issues
Definition

1-Sensitivity of the information-how personal is the data? 2-Sensitivity of the collection location-some settings are inherently more private than others 3-Privacy of information-No identifiable information released 4-Anonymity-No one knows your name at any point during the test 5-Confidentiality-Individuals conducting the test know your name but do not release it to the public

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