Flashcards in quiz 2 Deck (65)

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1

## Explain a randomized control trial

###
When you take a group of volunteers, and randomly assign them to two groups.

One groups gets an intervention and the other gets a non-intervention or placebo. These two groups are compared to see if there's a difference between them overtime.

2

## What is a confounding variable?

### An alternative explanation for a relationship that has been observed

3

## Why are RCTs good at dealing with confounding variables?

### In an RCT, the confounding variable will equally affect both of the randomly split group in the RCT

4

## What is a population?

### persons, objects, or events that meet a specific set of criterias

5

## What is a target population?

### the larger population to which results of a study will be generalized to

6

## What is an accessible population

### the actual population of subjects available to be chosen for a study. (a subset of the target population)

7

## What is a sample?

### a subgroup of the accessible population which allows the results to be generalized to the population

8

## What is a sampling bias?

### the extent that sample SYSTEMATICALLY misrepresents populations. Can be conscious or unconscious

9

## What is a sampling error?

### the extent that a sample RANDOMLY misrepresents population

10

## What are the types of sample techniques?

### Probability samples and non-probability samples

11

## What is a probability sample?

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Random selection (or other known probability). Sample is considered, representative of population(although it may not be).

Can estimate sampling error

12

## What is a non-probability sample?

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Non-random samples. Generalization is difficult.

Can't estimate sampling error (should not use inferential statistics)

13

## Types of probability sampling

### Simple random sampling, systematic sampling, stratified random sampling, and cluster sampling

14

## What is simple random sampling?

### Random sampling. Everyone has an equal chance of getting in the study

15

## What is systematic sampling?

### systematically choosing samples. Ex: selecting every 10th person from a group. So you can estimate the probability of a person being in the sample

16

## What is stratified random sampling?

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specifying a number from each category in the sample.

Ex: 20 students from each grade level

17

## What is a cluster sampling?

### multi-layer/stage

18

## Types of non-probability sampling

### convenience sampling, quota sampling, purposive sampling

19

## What is convenience sampling?

### when subjects are chosen on basis of availability. This is the most common form

20

## Types of convenience sampling

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- Consecutive sampling: recruit everyone to meet inclusion/exclusion criteria

- Volunteers(flyers/ads): what attributes lead subjects to volunteer & potential bias of self-selection

21

## What is quota sampling?

### Like stratified, where you select a specific amount from each category, but this is not random

22

## What is purposive sampling?

### where subjects are hand-picked by specific criteria. Ex: case series

23

## What is an extraneous variable?

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any factor not related to the purpose of the study, which may affect dependent variables.

- can become confounding variable if uncontrolled

24

## 3 essential components of experimental research

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- include a control or comparison group.

- independent variable manipulated by the experimenter

- subjects are randomly assigned to groups, as opposed to naturally occurring or provider choice

25

## What is random assignment?

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each subject has an equal chance of being assigned to any group.

- helps control for extraneous variables or prognostic indicators

26

##
Random sampling is used to ____.

Random assignment is used to _____.

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Generalize to a population.

Equalize two groups (controls and experimental)

27

## What is concealing allocation?

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Separating people should do the "random assignment" & data collection.

Sealed envelopes and locked cabinets

28

## What is blinding?

### To control conscious & unconscious bias in anyone involved in a study.

29

## What is a single blind?

### A case where just the measurer is blinded

30