Topic 5 and 6 Sampling and Data collection

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

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 eg 40% of population is male so try to make sure 40% of sample is male.

Question 7

STRATIFIED RANDOM SAMPLING

Answer 7

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

Question 8

Why are eligibility criteria so important?

Answer 8

Characteristics specific to allow generalisability of findings

Question 9

What is/are the MAIN purposes of sampling

Answer 9

• Increase efficiency of study

* Maintain representativeness of sample

Question 10

Name 2 MAJOR headings under which samplings falls

Answer 10

• Probability

* Non-Probability

Question 11

What are the advantages of random sampling?

Answer 11

• No researcher bias

* Maximise representativeness

Question 12

What is the aim of stratified random sampling?

Answer 12

Increase representativeness

Question 13

What are the advantages of non-probability sampling?

Answer 13

• Less Rigorous
• Limits generalisability
• Not representative

Question 14

Name 4 qualitative data collection methods

Answer 14

1. In depth interviews
2. Focus groups
3. Secondary data/document review
4. Observations

Question 15

In depth interviews may be:

Answer 15

Structured, Semi-structured or unstructured

Question 16

Focus Groups:

Answer 16

Involve multuple participants discussing an issue

Question 17

Secondary data/document review:

Answer 17

Diaries, written accounts of past events, photographs

Question 18

Observational:

Answer 18

May be onsite, or under ‘laboratory co ditions, for example where participants are asked to role-play a situation to show ehat they might do.

Question 19

How is trustworthiness/rigor assured in qualitative research?

Answer 19

1. Credibility (truthfulness)
2. Auditability (consistency)
3. Transferability (fittingness/applicability )
4. Confirmability (no bias or distortion )

Question 20

Why is rigor so important?

Answer 20

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

Question 21

List four quantitative data collection methods.

Answer 21

1. Physiological
2. Observational
3. Questions & Self-report scales-questionaires
4. Interviews

Question 22

Physiological data collection includes

Answer 22

Laboratory-based : experiments and clinical trials

Question 23

Observational

Answer 23

Observing and recording well-defined events eg counting the number of patients waiting in emergency at specified times of the day.

Question 24

Questions & Self reporting Scales- questionaires

Answer 24

Administering surveys with closed-ended questions, questionnaires.

Question 25

Interviews

Answer 25

Face-to-face snd teleohobe interviews

Question 26

Define Reliability in relation to measurement error

Answer 26

A measure can be relied upon consistently to give rhe same results if the aspect being measured has jot changed

Question 27

Define Validity in relation to measurement error

Answer 27

How accurately the measure yeilds 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 28

Descriptive statistics allow researchers to:

Answer 28

Describe, organise & summarise raw data

Question 29

Inferential statistics allows researchers to:

Answer 29

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

Question 30

The purpose of descriptive statistics is to ……….. and ……….. the data

Answer 30

*Organise and *Summarise

Question 31

Name 4 levels of measurement in quantitative data analysis and briefly define each of these:

Answer 31

1. Nominal :discrete categories 2. Ordinal: relative ranking
2. Interval; specific numerical distance between scores-treated as equal;continuouse.
3. Ratio: as above but has absolute zero.

Question 32

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

Answer 32

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

Question 33

Define Cross sectional Studies:

Answer 33

Collect all data at one point in time

Question 34

Define Longitudinal Studies:

Answer 34

Collect data at different points in time

Question 35

Define Retrospective studies:

Answer 35

Collect data on past events

Question 36

Define Prospective Studies

Answer 36

Collect data as they occur

Question 37

Manipulated variable (cause).
Used to predict outcome of interest ie dependent variable :

Answer 37

INDEPENDENT VARIABLE

Question 38

Measured variable (effect) 
Consequence/presumed effects that change with change in independent variable:

Answer 38

DEPENDENT VARIABLE

Question 39

Name 2 types of validity

Answer 39

Internal Validity and External Validity

Question 40

Internal Validity

Answer 40

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

Question 41

External Validity

Answer 41

Deals with problems of generalisability of findings to others populations and other environmental cobditions.