week5-6

Question 1

Population?

Answer 1

• well-defined group with specific characteristics

- all the individuals the researcher is interested in studying

Question 2

Sample?

Answer 2

subset of overall population

-set of elements that make up population

Question 3

Convenience sample?

Answer 3

All members of the population with the relevant characteristics who can be readily found (and consent)

Question 4

Snowball sampling?

Answer 4

A participant refers the researcher to more potential participants, who may then refer
researcher to further potential participants (snowballing).

Question 5

Purposive sampling?

Answer 5

An intentional (purposeful) approach is made by the researcher to select participants with specific characteristics or participants within a specific area.

Question 6

Quota sampling?

Answer 6

A sample gathered to represent population as closely as possible e.g. 40% of population is male so try to make sure 40% of sample is male

Question 7

Simple random sampling?

Answer 7

Participants allocated ‘randomly’ to the study or part of a study: ‘pulled out of a hat’ chosen by computer.

Question 8

Stratified random sampling?

Answer 8

Members of the population allocated to groups according to characteristics important to the study and then subjects randomly chosen from these groups

Question 9

Why are eligibility criteria so important?

Answer 9

Characteristics specific to allow generalisability of findings

Question 10

What is/are the main purpose(s) of sampling?

Answer 10

Increase efficiency of study

Maintain representativeness of sample

Question 11

Name the two major headings under which sampling falls?

Answer 11

Probability

non-probability

Question 12

What are the advantages of random sampling?

Answer 12

No researcher bias

Maximise representativeness

Question 13

What is the aim of stratified random sampling?

Answer 13

Increase representativeness

Question 14

What are the disadvantages of non-probability sampling?

Answer 14

Less rigorous
Limits generalisability
Not representative

Question 15

Name four qualitative data collection methods

Answer 15

In-depth interviews: may be structured, semi-structured or unstructured

Focus groups: involve multiple participants discussing an issue

Secondary data/document review: diaries, written accounts of past events, photographs

Observations: may be on site, or under ‘laboratory conditions’, for example, where
participants are asked to role-play a situation to show what they might do.

Question 16

How is trustworthiness/rigor assured in qualitative research?

Answer 16

Credibility (truthfulness)
Auditability (consistency)
Transferability (fittingness/applicability)
Confirmability (no bias or distortion)

Question 17

Why is rigor so important?

Answer 17

Need to know methods can be trusted and can have confidence in results, and using them
ie applying in clinical practice

Question 18

List four quantitative data collection methods.

Answer 18

Physiologic/laboratory-based: Experiments/clinical trials

Observational: Observing and recording well-defined events (e.g., counting the number of patients waiting in emergency at specified times of the day) Questions & self-report scales-

questionnaires: Administering surveys with closed-ended questions questionnaires

Interviews: face-to face and telephone interviews

Question 19

Define reliability and validity in relation to measurement error.

Answer 19

Reliability means: that a measure can be relied upon consistently to give the same result if the aspect being measured has not changed.

Validity reflects how accurately the measure yields information about the true or real variable being measured. A measure is valid if it measures correctly & accurately what it is intended to measure

Question 20

Descriptive statistics allow researchers to:

Answer 20

describe, organise & summarise raw data

Question 21

Inferential statistics allow researchers to:

Answer 21

Estimate how reliably they can make predictions & generalise their findings based on the data

Question 22

The purpose of descriptive statistics is to?

Answer 22

organize and summarise the data

Question 23

Name four levels of measurement in quantitative data analysis and briefly define
each of these:

Answer 23

Nominal: discrete categories
Ordinal: relative ranking
Interval; specific numerical distance between scores- treated as equal; continuous
Ratio: as above but has absolute zero

Question 24

Name and briefly describe the three most common measures of central tendency?

Answer 24

Mean: average score
Median: middle score
Mode: most common score

Question 25

Cross-sectional studies?

Answer 25

collect all data at one point in time

Question 26

Longitudinal studies?

Answer 26

collect data at different points in time

Question 27

Retrospective studies?

Answer 27

collect data on past events

Question 28

Prospective studies?

Answer 28

collect data as they occur

Question 29

Independent variable?

Answer 29

manipulated variable (cause)
used to predict outcome of interest ie dependent variable

Question 30

Dependent variable?

Answer 30

measured variable (effect)
consequence/presumed effect that changes with change in independent variable

Question 31

Name two types of validity and briefly define each

Answer 31

Internal validity: does the independent variable accurately measure what it says it will measure. Asks whether independent variable really made the difference- refers to the causal relationship

External validity: deals with problems of generalisability of findings to other populations and other environmental conditions