Exam 3

Question 1

What is the difference between a study completed using a sample and a census?

Answer 1

A study using a sample is a representational portion of the total population while a census is meant to be a study of the ENTIRE population

Question 2

What is sampling error?

Answer 2

When the sample does not properly represent the population.

Question 3

What is the difference between biased (non-probability) and representative samples (probability)?

Answer 3

A biased sample is more typically used in research due to the difficulty of creating a truly representative sample (availability of college students vs the entire population).

Question 4

How do researchers create biased samples?

Answer 4

Self-selected sample (volunteers), snowball sampling (word of mouth), purposive sampling (cluster sampling, targeting a specific group, posting study fliers within a gay bar), quota sampling (stratified sampling, requiring a specific amount of specific participants)

Question 5

What is a multistage sample?

Answer 5

Sampling participants in multiple stages, choosing a random sample of clusters and then randomly sampling from the chosen clusters

Question 5

Why are representative samples better than biased samples?

Answer 5

Representative samples have higher external validity due to being perfectly representative of the population.

Question 6

What is cluster sampling?

Answer 6

Biased, choosing clusters participants within a population (pre-k teachers vs high school teachers)

Question 7

What is a stratified random sample?

Answer 7

Choosing a specific characteristic to sort the population (male vs female) and making sure that this characteristic is properly represented in the sample of the population

Question 8

What is the benefit of oversampling?

Answer 8

When sampling a minority population, it may be importance to focus on gathering minority participants instead of the majority (When studying non-binary individuals, it is important to ensure that the sample is representative of the non-binary population through oversampling)

Question 9

Define external validity.

Answer 9

When the concept being studied can be broadly applied to the population (hours slept and how this impacts all human tasks).

Question 10

Define internal validity.

Answer 10

When the concepts within a study interact and influence one another (hours slept vs score on math test).

Question 11

Define statistical validity.

Answer 11

When a study is confirmed through statistics.

Question 12

Define construct validity.

Answer 12

How accurately the construct is defined and measure.

Question 13

What shows the strength of the correlation?

Answer 13

How close ‘r’ is to 1.0

Question 13

Does the sample size impact external validity?

Answer 13

No, the method of sampling impacts the external validity much more than the overall size

Question 14

What is the point of ‘r’?

Answer 14

The r value shows the strength of the statistical relationship between variables (SES vs Level of Education)

Question 15

Does the type of statistical analysis impact the claim of the study?

Answer 15

No, the type of test does not determine the type of claim a study can make (causal claims).

Question 16

What types of studies typically use a t-test for statistical analysis?

Answer 16

Manipulation/experiments

Question 17

What types of studies typically use a correlational test for statistical analysis?

Answer 17

Measured variables/association

Question 18

Why don’t the typical rules for understanding a correlational analysis apply to a curvilinear result?

Answer 18

The results are significant on both sides of the data (serial position effect)

Question 19

What are spurious correlations?

Answer 19

A spurious correlation is a possible outlier influence/reason for the significance of the correlation that does not include the two variables

Question 20

Define moderation.

Answer 20

When the relationship between two variables changes depending on the level of the third variable (shows different associations between original variables, maternal employment influences their child’s vocabulary ability, but the mother’s marital status also has a big influence)

Question 21

Are spurious correlations and moderator variables related?

Answer 21

Yes, they can be one in the same, (kidnapping rates and number of vacations taken within one year, proximity to an airport)

Question 22

What is a multivariate correlational design?

Answer 22

More than two measured variables and their correlation

Question 22

How does the number of variables measured by researchers impact the control over confounds within a study?

Answer 22

With the presence of more variables, the researchers are able to cross examine the data and determine which of the variables truly had the influence ``

Question 23

How is one way to improve internal validity?

Answer 23

Through measuring more variables

Question 24

What is the defining characteristic of a regression analysis?

Answer 24

Regressions are used to decide whether variables can predict a separate variable (SATs to college GPA)

Question 25

What is the function of Beta (standardized coefficient?

Answer 25

Beta is used to quantify the standard deviation between variables (average change that the variables cause)

Question 26

What is the function of regression coefficient b (non-standardized coefficient)?

Answer 26

Coefficient b is used to quantify the single unit of change the variables cause (this is why it cannot be generalized for all b's)

Question 27

What is the purpose of including all of the variables within the regression equation (even if they weren't significant)?

Answer 27

In order to control for confounds, therefore their minimal (possible) impact is included

Question 28

What are some ways to tell that a multiple regression has been used in a study?

Answer 28

- "Controlled for" - "Taking into account" - "Corrected for" - "Adjusting for"

Question 29

What is the most important limitation to a multiple regression?

Answer 29

Alone, an MR study does not establish causation

Question 30

Why can't an MR study establish causation?

Answer 30

An MR study is unable to establish temporal precedence, a longitudinal design is also required

Question 31

Define parsimony?

Answer 31

Choosing to use the best explanation that requires the fewest exceptions or qualifications (apple falls down because the atmosphere around causes the apple to fall, instead of the apple falls because it wants to be back to its most natural place)

Question 32

What is a mediation model?

Answer 32

Proposed variables that influence one another, typically used in clinical settings (many reasons for anxiety/depression)

Question 33

What is mediation used for?

Answer 33

To prove temporal precedence within a regression study (SAT's predict college GPAs, multiple variables contribute to this such as ability to do tasks under a stressful time requirement, logic, and comprehension skills)

Question 34

How do we establish causation within a study?

Answer 34

Covariance (r), temporal precedence, and internal validity

Question 35

How do we establish temporal precedence within a correlational/regression study?

Answer 35

Longitudinal design

Question 36

What are the types of longitudinal results?

Answer 36

cross-sectional correlation, autocorrelation, andcross-lag correlation

Question 37

Define cross-sectional correlation.

Answer 37

The association is measured between two variables at the same point in time (violence in children and videogame preference at 14)

Question 38

Define autocorrelation.

Answer 38

The association between the same variable is measured at different points in time (Violence in children at 4 and then at 14)

Question 39

Define cross-lag correlation.

Answer 39

The association between all the variables at once (violence and videogame preference in 4 and 14 y/o)

Question 40

Why do a correlational study instead of an experiment?

Answer 40

It opens up the opportunity for studies that may be unethical/unable to be manipulated (smoking studies/videogame preference)