Research Design Flashcards Preview

SBM II December > Research Design > Flashcards

Flashcards in Research Design Deck (54):
1

What are Observational Studies?

A type of study in which individuals are observed or certain outcomes are measured. No attempt is made to affe the outcome (for example, no treatment is given)
--In other words, not a "controlled" study where we try to manipulate some variable

2

What are other names for Observational Studies?

Epidemiology, Prevalence study, descriptive study

3

How can observational studies be done?

-Can be cross-sectional or longitudinal; qualitative, quantitative or mixed-methods

4

What are Cross-Sectional Studies?

-Snapshot of sample
-One point in time
-Cost effective
-Can't capture change
-More common than longitudinal
-Size of study does not matter
-It is the number of assessments or the number of points of data collection that differentiate these!

5

What are Longitudinal Studies?

-Two or more time periods
-More complex
-More expensive
-More powerful - captures change - aims for nomothetic causality
-Descriptive & Explanatory

6

What are three types of Longitudinal Studies?

1. Trend
2. Cohort
3. Panel

7

What are Trend Longitudinal Studies?

Measure changes in a population over time (ex: survey of college freshman each year)

8

What are Cohort Longitudinal Studies?

Measures changes and follow a particular population over time.
(ex: Survey 25 MS1 students in 2012, then any 25 again in 2013 as MS2 students and so on. Same cohort, but potentially different people sampled).

9

What are Panel Studies?

Measure changes in the SAME people over time.
(ex: enroll 200 diabetic patients in a study in 2013. Re-interview the same patients in 2014 and again in 2015)
[OFTEN SAME THING AS COHORT IN BOARDS]

10

You follow a sample of 500 smokers for 10 years to determine the occurrence of COPD. You will interview participants annually. Correct identification of study design would include:

A. Panel study (in biostats books, potentially called a cohort study)
B. Longitudinal Study
C. Observational Study

11

Incorrect identification of study design would include: (in COPD case)

A. Cross-sectional study
B. Case-control study
C. RCT
D. Experiment

12

What are 3 positives about Observational Studies?

1. Often incorporate probability sampling for generalizability
2. Great tool for building a knowledge base and exploring new topics
3. Might allow us to answer some questions that controlled suited cannot (for moral and ethical reasons)

13

What are 3 negatives about Observational Studies?

1. Validity of measures across cultures (if using survey)
2. Findings are associations or correlations, not causality (causality requires time order, non-spuriousness, and association)
3. Often rely on survey self-reports, not actual behavior (but can incorporate other types of data, e.g., chart reviews, multiple reporters)

14

What are Qualitative studies?

-High validity, allows us to explore depth, nuance.
Examples: Focus Groups, Qualitative personal interviews, non-obstructive measures, visual methodologies, etc.

15

What are Quantitative studies?

-High reliability, often coupled with generalizable sampling procedures
--> Quantitative = quantify

16

What are Mixed Methods?

Using both Qualitative and Quantitative studies

17

What are four more things on Qualitative Research?

1. Entails analysis of less structured data (e.g., open ended responses, social artifacts)
2. Excellent tool for exploratory research
3. Growing acceptance in medication research (e.g., NIH), esp. if used in mixed-methods studies
4. Many software programs to aid analysis

18

What is RCT?

Randomized Controlled Trials or Clinical Trials

19

What are Experiments good for?

Mode of scientific observation.
Good for hypothesis testing -determine *causation
--> Take a group
--> Apply an action
--> Examine effects of the action

20

What supports a causal association in RCT?

Reproducibility of the Data

21

What are the three main parts of a Classical Experiment?

1. IV and DV
2. Pretesting and post-testing
3. Control and Experimental Groups

22

What are the Independent and Dependent variables?

Independent = Cause/Stimulus
Dependent = Effect

23

What is change attributed to in experiments?

Independent Variable

24

What is the difference between the experimental group and the control group?

Exp. group = gets the stimulus
Control group = does not receive stimulus (may receive placebo or some other comparative treatment)
-->Compare both groups to examine effect of stimulus
-->Guard against events outside the experiment

25

In an experiment, what do you measure before and after adding a stimulus?

Dependent variable

26

What is the main purpose of Phase I Clinical Trials?

Safety and side effects in heathy patients

27

What is the main purpose of Phase II Clinical Trials?

Ideal dosing in diseased patients

28

What is the main purpose of Phase III Clinical Trials?

Experimental treatment vs. control

29

What is the main purpose of Phase IV Clinical Trials?

Continued evaluation of FDA- approved therapy for long term effects

30

What is the Hawthorne Effect?

Researcher attention affects behavior

31

What is Double-blind?

Researcher and respondents don't know control or exp.

32

What is a One-shot case study?

Apply stimulus, measure DV afterwards

33

What is One-group pretest-posttest?

Measure DV, apply stimulus, measure DV

34

What is Static-group comparison?

-Two groups
-Only one gets the stimulus
-No pre-test

35

What is External Invalidity?

Applicability to the real world is lacking.

36

What is Internal Invalidity?

Anything other than the stimulus that influences results.

37

What are sources of Internal Invalidity?

-History
--> Current Events
-Maturation
--> People change over time
-Testing
--> Act of testing will influence behavior
-Instrumentation
--> Any change in instrumentation can influence results

38

What can invalidate Statistical Regression?

Extremes can bias stimulus results

39

What can invalidate Selection bias?

Groups need to be comparable

40

What can invalidate Experimental mortality?

Subjects drop out of experiment

41

What can invalidate causal time order?

Cause must come before the effect

42

What can diffusion of treatments do to a study?

Contamination of the control group

43

What can compensation do to a study?

Incentive or stimulus may bias groups

44

What can compensatory rivalry do to a study?

Control group may try to make up for lack of stimulus

45

What can demoralization do to a study?

Control group may become discouraged by the lack of stimulus

46

What is the weakness of experimental designs?

Artificiality

47

What are the strengths of experimental designs?

-Isolating IV (causal influence)
-Easy to replicate
-Scientifically rigorous

48

What is another name for Experimental?

Clinical trail

49

What is another name for Cross-sectional?

Prevalence

50

What is another name for Retrospective?

Case-control

51

What is another name for Prospective?

Cohort Study (a type of longitudinal observational design)

52

What is controlled (experimental) research?

In some texts and writings, compared against all other types of "non-controlled" studies

53

What are Observational Studies?

-Case-Control (A type of observational study)
-Also case-history study
-Often compares diseases or events or exposures that have happened already. "Cases" are compared to non-cases, or "controls" in relation to certain risk and protective factors.
-The term retrospective often accompanies this case-control design in biostats writings, although any report or point of data from the past can be viewed as retrospective

54

What is an example of observational studies?

A group of recently pregnant women who had miscarriages is compared to a group of women who went to full term. The groups are interviewed about caffeine use during their first trimester to look for a correlation between caffeine and miscarriage (Note potential for recall bias)