HRSS Sampling types

Question 1

What is sampling Bias

Answer 1

Sampling bias occurs when the members of a sample over or under represent attributes of the population that are related to areasd being studied

Question 2

What is probability sampling

Answer 2

The probability of each individual being selected can be claculated and is usually made to be an equal chance

Question 3

What are the 5 types of probability sampling

Answer 3

Random Sampling
Systematic sampling
stratified tandom sampling
disproportionalte sampling
cluster sampling

Question 4

Simple random sampling

Answer 4

purest form of sampling with each member having equal chance of being selected - reduces systematic bias

Question 5

Systematic sampling

Answer 5

Every nth subject from a population list is chosen instead

Question 6

stratified random sampling

Answer 6

population is split into groups of similar individuals (strata) from which a simple random sample is drawn

involves identifying relevant characteristics and partitioning members of a population into homogenous, non-overlapping subsets based on these characteristics

Question 7

two types of numeric variables

Answer 7

continuous/scale - arise from measurements

Discrete variables arise from counting

Question 8

two types of categorical variables

Answer 8

Nominal - No natural order

Ordinal variables have a natural order

Question 9

Disproportionate sampling

Answer 9

if the strata in a population are unequal in size then stratified sampling may give inadequate sample sizes for comparison

Question 10

Cluster sampling

Answer 10

Involves the successive random sampling of a series of units in a population - cluster sampling is convenient and efficient but may compound the effects of ssampling bias

Question 11

4 methods of non-probability sampling

Answer 11

Convenience sampling
quota sampling
purposive sampling
snowball samplin

Question 12

Convenience sampling is

Answer 12

Subjects are chosen on the basis of their availabiltiy

Question 13

Quota Sampling

Answer 13

Researcher guides the sampling process until the participant quota is met e.g malels and females

Question 14

Purposive sampling

Answer 14

Hand picked based on certain criteria

Question 15

Snowball sampling

Answer 15

Used when the desired characteristics of the required sample are rare - it relies on original participants identifying or referring other people

Question 16

2 types of experimental

Answer 16

1. Experimental

2. Quasi-experimental

Question 17

Observational studies - cccpc

Answer 17

Cohort - longitudinal

case-controlled - e.g cases with a given attribute are compared to controls without that attribute

cross sectional
prevalence
case report

Question 18

Observational

Answer 18

Subjects observed in their natural state, can prospective or retrospective

Question 19

RCT

Answer 19

Two or more groups are allocated randomisation

• -> on group receives experimental variable and the other group acts as a control
• -> changes from pre to post test that appear in the experiemental, but not the control group can be reasonably attributed to the treamtnet

Question 20

Quasi experimental designs

Answer 20

One group posttest-only design

one group pretest-posttest design

nonquivalent control group design

non-equivalenet control group pretest-posttest design

single subjects design