Module 7: Quantitative Research Designs

Question 1

What are the 3 broad design categories used in quantitative research?

Answer 1

1. Nonexperimental/observational
2. Quasi-experimental
3. Experimental

Question 2

Nonexperimental/Observational studies can be either ______ or ______.

Answer 2

descriptive (correlational or univariate)

correlational/relationship (retrospective or prospective)

Question 3

What do descriptive correlational studies show?

Answer 3

A relationship between two variables (whether or not they covary) without looking for explanation or causality

Question 4

What do univariate descriptive studies do and what are the two types?

Answer 4

They describe the occurrence of something

1. Prevalence (cross-sectional)
2. Incidence (longitudinal)

Question 5

How are prevalence (cross-sectional) and incidence (longitudinal) univariate descriptive studies different?

Answer 5

Prevalence studies that are cross-sectional explore the occurrence of something at one point in time. Incidence or longitudinal studies estimate the development of new events or new cases over time.

Question 6

What is a retrospective study?

Answer 6

A type of correlational/relationship nonexperimental study that links present phenomena to phenomena that has occurred in the past. The researcher begins with the dependent variable and examines whether or not it is correlated with one or more previously occurring independent variables

Question 7

What is a case control design?

Answer 7

A type of retrospective study (correlational/relationship nonexperimental study) which looks at similar groups of people, one which have a specific outcome and one which does not
(ex- similar people, one group with lung cancer and one without)

Question 8

What is a prospective or cohort study design?

Answer 8

A type of correlational/relationship nonexperimental study that starts with a presumed cause and then goes forward in time to the presumed effect
(strongest design for prognosis and etiology question when randomization is impossible)

Question 9

Which type of research study can be described as controlled trials without randomization?

Answer 9

Quasi-experimental studies

Question 10

Quasi-experimental Designs include: (4)

Answer 10

1. Pretest-posttest nonequivalent control group
2. After-only nonequivalent control group
3. One group pretest-posttest
4. Time series

Question 11

How is a time series experiment conducted?

Answer 11

(quasi-experimental)
Data about the dependent variable is collected over an extended period during which an intervention is introduced and following the intervention. Repeated measures

Question 12

In experimental and quasi-experimental designs researchers use an ___________ to bring about a desired effect.

Answer 12

Intervention

Question 13

How is systematic bias reduced?

Answer 13

Randomization

Question 14

Experimental Designs include what 5 types?

Answer 14

1. True experimental (RCT)
2. Pretest-Posttest
3. Posttest Only
4. Factorial
5. Crossover

Question 15

What are some design features of True experiments (RCTs)?

Answer 15

Manipulation
Control
Randomization
Blinding

Question 16

Which variable is manipulated in an RCT?

Answer 16

Independent variable
(researchers used manipulation to do something to study participants)

Question 17

What are examples of control groups used in RCTs?

Answer 17

Patients receiving a placebo

Standard of care practices

Question 18

Blinding in an RCT is used to decrease bias that comes from ________ .

Answer 18

Awareness

Question 19

In randomization participants have an ________ chance of being placed in groups randomly.

Answer 19

equal

Question 20

How is the pretest-posttest design of an experiment conducted?

Answer 20

Outcome variable data is measure on both groups before the intervention and again after the intervention

Question 21

What is a downside to posttest only experimental designs?

Answer 21

Not testing the participants prior to the intervention doesn’t allow the researchers to know if the groups were the same prior to the intervention

Question 22

In a pre-test post test design where participants have data collected from them at multiple post intervention points this is called________ _____ _____.

Answer 22

repeated measures design

Question 23

What is factorial experimental design?

Answer 23

A design that allows for manipulation of two or more variables (factors) simultaneously

Question 24

In addition to ‘main effects’ (those from experimentally manipulated variables) factorial designs also allow researchers to test _________ _______ .

Answer 24

Interaction effects

Question 25

How is a crossover experimental study conducted?

Answer 25

The same participants are exposed to more than one condition and serve as their own controls

Question 26

When can a crossover experimental design not be used?

Answer 26

When there is expected carry over effect from one condition to another.

Question 27

To avoid carryover effect in a crossover experimental study what do researchers sometimes allow for?

Answer 27

Washout period in between treatments

Question 28

What aspect of correlational research. related to sampling, is a weakness?

Answer 28

Self-selection of groups