Lecture 2 - Research Design

Question 1

What is a research aim?

Answer 1

• A statement describing the purpose of the study
• A short, concise “catchy” re-statement of the research topic or theme

Question 2

What is a research question?

Answer 2

• What the study aims to answer after data analysis and interpretation

• Must be specific and concise to provide a clear foundation for the hypotheses

Question 3

What are the three types of research questions?

Answer 3

• Descriptive

• Comparative

• [UNFINISHED]

Question 4

Describe and give an example of a descriptive research question

Answer 4

• Present variables to measure or analyse

• “What is the proportion of elite triathletes who take vitamin supplements?”

Question 5

Describe and give an example of comparative research questions

Answer 5

• Clarifies the difference in an outcome variable between two or more groups

• Compares the effects of variables or interventions

• “Is there a difference between males in females in reaction time?”

• “Is quadriceps power improved more by resistance training or sprint training?”

Question 6

Describe and give an example of [?] research questions

Answer 6

• Defines trends, associations or interactions between variables

• “Is there a relationship between number of exams and perceived stress levels among undergraduate students?”

Question 7

What are the two acronyms for criteria for good research questions?

Answer 7

• FINER

• PICOT

Question 8

What does the FINER acronym stand for?

Answer 8

• Feasible - appropriate number of participants and technical expertise, affordable in time and money, and manageable in scope

• Interesting - getting the answer intrigues the investigator, peers and the community

• Novel - confirms, refutes or extends previous findings (or discovers something new)

• Ethical - consistent with the standards that will lead to ethical approval

• Relevant - to scientific knowledge and/or applied practice

Question 9

What does the PICOT acronym stand for?

Answer 9

• Population - what specific group are you interested in?

• Intervention - what is the intervention you are investigating (if it’s an intervention study)

• Comparison - what is the alternative to compare with the intervention?

• Outcome - what do you intend to accomplish, measure, improve or affect?

• Time - what is the appropriate follow up time to assess the outcome?

Question 10

What is a research objective?

Answer 10

• Objectives define specific aims and explain how the overall aim is achieved

• Translates the overall aim into operational statements, tells the reader how the overall aim will be achieved, and may even specify how a variable is measured if this is important

Question 11

What is a research hypothesis?

Answer 11

A specific, clear and testable statement about the possible outcome of a study

Question 12

What are the two traditional hypotheses?

Answer 12

• Null hypothesis

• Alternate hypothesis

Question 13

What are the six types of research hypotheses?

Answer 13

• Simple

• Complex

• Directional

• Non-directional

• Associative

• Causal

Question 14

What is a simple hypothesis?

Answer 14

It predicts the relationship between a single dependent variable and a single independent variable

Question 15

What is a complex hypothesis?

Answer 15

Predicts the relationship between multiple dependent and independent variables

Question 16

What is a directional hypothesis?

Answer 16

Identifies the direction of the relationship between variables

Question 17

What is a non-directional hypothesis?

Answer 17

Does not specify a direction of effect (intentionally)

Question 18

What is an associative hypothesis?

Answer 18

Change in one variable is associated with change in another (but may not be causal)

Question 19

What is a causal hypothesis?

Answer 19

Manipulating the independent variable will change the dependent variable

Question 20

Why is research design important?

Answer 20

• To provide a framework of methods and techniques

• Enables research to be conducted in a structured way

• Research design tells us “how” a study is conducted

Question 21

What is the difference between an observational study and an experimental study?

Answer 21

• Observational studies have no intervention whereas experimental studies involve an intervention

• Observational studies provide information on associations between an ‘exposure’ and an ‘event’ or ‘characteristics’ of the population

• Experimental studies allow for the determination of cause and effect if the study is designed appropriately

Question 22

What are the differences between cross-sectional and longitudinal studies?

Answer 22

• Cross-sectional studies assess a phenomenon at one point in time, whereas longitudinal studies assess a phenomenon at several points in time

• CS measure different samples/populations whereas longitudinal ensure the same sample/population over time

• CS provides a snapshot of a given point in time, whereas longitudinal provides information on change at an individual level

• CS examines trends and changes at a societal/national/international level whereas longitudinal examines changes in the same people over time

Question 23

What is retrospective design?

Answer 23

Backwards looking - examine data that already exists

Question 24

What is prospective design?

Answer 24

Forward looking - collects new data, then sometimes watch/wait

Question 25

What is a case control study?

Answer 25

• Usually retrospective (but not exclusively) • “Cases” have the outcome (e.g. heart disease) • “Controls” do not have the outcome

Question 26

What is a randomised controlled trial?

Answer 26

• Forward looking (prospective) • Participants are randomised into a “control” or “intervention” group • Follows group over time to determine a difference in outcomes

Question 27

What are the three criteria for randomised controlled trials to prove cause and effect?

Answer 27

• The cause must precede the effect • The cause and effect must be correlated • The correlation between cause and effect cannot be explained by another variable

Question 28

What are the threats to internal validity in a randomised controlled trial?

Answer 28

• History - an unintended event during the study has an influence • Maturation - processes within participants that happen due to time • Testing - learning effect of multiple testing (e.g. scoring higher in cognitive function test second time) • Instrumentation - changes in instrument calibration, staff performing procedures differently • Statistical regression - non-random selection (e.g. self report or measurements) lead to values that are less extreme • Selection bias - non-random selection or a specific condition biases the study and may explain the results • Experimental mortality - loss of participants • Selection-maturation interaction - if key variables interact with time and if one group is fated more than another • Expectancy - experimenters expect one group to perform better

Question 29

What are the threats to external validity in a randomised controlled trial?

Answer 29

• Reactive or interactive effects of testing - any pre testing makes the intervention more effective • Interaction of selection bias and treatment/intervention - when a group is selected for a particular characteristic and the treatment only works with these participants • Reactive effects of experimental treatment - the treatment/intervention only works under controlled laboratory conditions and may not be effective in the real world • Multiple treatment interference - when participants receive more than one treatment/intervention and the effects of the other treatment affects the results

Question 30

What is internal validity?

Answer 30

Whether the study design, conduct and analysis answer the research question without bias

Question 31

What is external validity?

Answer 31

Whether the study findings can be generalised to other contexts

Question 32

What can you do to control threats to internal validity?

Answer 32

• Randomisation • Placebo controls • Blinding

Question 33

What can you do to control threats to external validity?

Answer 33

• Randomisation • Selecting tests, interventions and participants that are representative and generalisable

Question 34

What is a quasi-experimental design?

Answer 34

An intervention study that does not randomise participants and/or have a control group

Question 35

What are feasibility studies?

Answer 35

• Research done before a main study to determine whether the methods are feasible and acceptable

Question 36

What are pilot studies?

Answer 36

A small-scale study conducted prior to a large-scale experiment to test and refine procedures

Question 37

What is epidemiology?

Answer 37

The study of the occurrence and distribution of health-related events, states, and processes in specified populations, including the study of the determinants influencing such processes, and the application of this knowledge to control relevant health problems

Question 38

What are the ways to assign people to groups?

Answer 38

• Random assignment - randomly allocate participants to different study groups • Random matched assignment - considering a participant characteristic • Intact groups - not randomising (if it’s not possible - there are post-hoc justifications)