Week 5: Experimental Research and Threats to validity

Question 1

Explain the difference between a case control and a cohort study?

Answer 1

Case Control - Gather people with (cases) and without (controls) disease Look back at dietary behaviours using self-reported measures.
Cohort Study - Descriptive, nothing to look back on, no intervention. Follow people for a period of time and gather data on dietary behaviours When disease emerges compare behaviours between groups.

Question 2

Explain the difference between subjective and objective?

Answer 2

Subjective - “Biased” Open to interpretation Usually gathered using questionnairesSelf-report measures are common.
Objective - “Unbiased” Not open to interpretation Usually gathered using instruments.

Question 3

Describe what an RCT is and whys it is considered the ‘holy grail’ of scientific research?

Answer 3

Randomizing Participants to Treatment or Control Groups allows us to assume that the groups are similar.

Question 4

Explain the differences between experimental, quasi-experimental, and pre-experimental research?

Answer 4

Experimental= does randomize participents, examines cause and effect.

Quasi= does not randomize treatment or control group

Pre-experimental= Selects a sample, runs a pre test, the treatment and then post test, BUT does not have anything to compare it to. (very weak design often used by industry-funded nutrition research.)

Question 5

Describe the concept of levels of evidence?

Answer 5

It is used to judge the strength of research on a particular topic