EBPS 2: Truth, Bias and Chance in Research

Question 1

Sampling

Answer 1

Choosing particular individuals from a population

Question 2

Census

Answer 2

where we study every individual in a population

Question 3

Experimental study

Answer 3

You intentionally manipulate an exposure by doing an “intervention” (usually with one or more control groups), and then see what happens

Randomized & non-randomized controlled trial

Question 4

Observational study

Answer 4

You just observe without any intervention
- Cross-sectional
- Cohort
- Case-control

Question 5

Target population

Answer 5

The population for whom the research question is relevant

Question 6

Accessible population

Answer 6

The population the researchers have access to and plan to study

Question 7

Study sample

Answer 7

the actual study subjects who were included in the study and whose data were analyzed and included in the study estimates

Question 8

Target phenomenon

Answer 8

The thing you want to learn about

Question 9

Intended variables

Answer 9

The things you think you can realistically measure in a research study

Question 10

Actual measurements

Answer 10

The measurements that are actually made (with error) for a study

Question 11

Inference

Answer 11

A conclusion reached on the basis of evidence and reasoning

Question 12

Estimate

Answer 12

Numerical best guess informed by data

Question 13

Point estimate

Answer 13

The single best guess estimate

Question 14

95% Confidence interval

Answer 14

The interval within which the TRUE parameter will be found 95% of the time (this helps us understand the precision of an estimate)

Question 15

Internal validity

Answer 15

How well do the study estimates represent what was intended in the study plan?

Question 16

External validity

Answer 16

How relevant are the study estimates to the research question?
- AKA: Generalizability
- Are study results applicable to the patient/population/problem in front of me?

Question 17

Random error

Answer 17

Error caused by chance (random processes)
- Lots of random error/chance = poor precision
- There can be random error in both sampling and measurement

Question 18

Systematic error

Answer 18

Error caused by non-random processes
- Lots of systematic error/bias = poor accuracy
- There can be systematic error in both sampling and measurement

Question 19

The Basic Research Cycle

Answer 19

1. research question
2. study design
3. drawing a sample of people to study
4. making measurements in that sample
5. analyze and interpret the data

Question 20

Measurement

Answer 20

making observations about the individuals who are sampled for the study
1. numeric (quantitative)
2. thematic (qualitative)

Question 21

intervention

Answer 21

intentionally expose people to something