Quantitative methods (4,7,16,17,19)

Question 1

Quantitative research

Answer 1

Quantitative research measures causes, effect relationships and correlations between
variables and enable researchers to see what is the most effective form of intervention.

Question 2

Aim of quantitative research

Answer 2

The aim is to test the hypothesis. The findings will either support or not support the
hypothesis.

Question 3

Variables

Answer 3

Variables: independent (presumed cause) and dependent (presumed effect)

Question 4

Examples of Quantitative research

Answer 4

Randomised controlled trials
Cohort studies
Case-control studies
Surveys

Question 5

Randomised controlled trials

Answer 5

Follow very strict procedures to make the process transparent.

Question 6

Hypothesis

Answer 6

Making a statement that predicts a direct relationship between a cause and its effect.

In an experiment it is the researcher’s job to rule out possible causes leaving only the most plausible explanation remaining- trying to isolate the cause and ruling out any other.

Question 7

Difference between independent variable and dependent variable

Answer 7

Independent variable- the cause and the dependent variable- the effect.

Question 8

What is H1 & H0

Answer 8

First hypothesis is labelled H1 and the null hypothesis is labelled H0.

Question 9

Sample size

Answer 9

Optimum number of participants
Too many- participants are burdened unnecessarily.
Sample size calculator

Question 10

Random sampling

Answer 10

Method of picking a sample from the study population where everyone has an equal chance of being chosen.

Question 11

Concealment

Answer 11

Blind studies are important to decrease biasness
Controversy about the placebo effect- the idea that people getting the placebo demonstrate relief of symptoms.
RCT need to report the process of concealment

Question 12

Data Collection: Randomised sampling

Answer 12

Data collection
Structured observations
Questionnaires

Question 13

Eligibility criteria

Answer 13

Potential inclusion of all those people who might have the characteristics needed for the study.
Often easier to state who is excluded first.
Might want to limit the age range
Should have a clear explanation of why the particular criteria has been selected.
Recruitment should be conducted using the principle of informed consent

Question 14

Types of bias

Answer 14

Selection bias- systematic difference between those selected into the sample and those not selected. Therefore, not a representative.

Allocation bias- a systematic distortion of the data.

Detection bias- differences in the assessment of the outcome between the experimental and control group.

Observational bias- contaminated observations by the observer’s belief, prejudice or background assumptions

Question 15

Types of bias (part 2)

Answer 15

Attrition bias- Systematic differences in the loss of participants from the experimental and control group

Confounding bias- occurs when a spurious association is made at the analysis stage between the intervention and the measurement which in reality results from a different or secondary measurement

Recall bias- differences in reporting experiences between those who have and those who do not have the outcome of interest occurs particular in retrospective studies

Publication bias- occurs when only the available literature is reviewed concerning a trail rather than all the literature pertaining to the trial