Quick Review Flashcards
Key components of a research question are…
– the associations between 2 or more variables
– the associations between exposure and disease states
– the association between an independent and dependent
variables
What are the two main types of study designs?
Observational and experimental
What are the types of observational study designs?
Cohort, cross-sectional, case-control
What is the type of experimental design study?
RCT
What is a cross-sectional study
Observational study that involves data collection from a population, or a
representative subset, at one specific point in time
What is a cohort study
observational study that is longitudinal and involves data collection from a group of
people over many points to examine factors related to an outcome (e.g. disease)
What is a case control study
observational study in which two existing groups differing in outcome (e,g., disease)
are identified and compared on the basis of some supposed causal attribute (i.e.,
exposure)
What is RCT
Control and experimental, random sampling, discover if there is a relationship between an independent and dependent variable
What is a continuous variable
Take on potential values within a given range
Ex: Age, Scores on an a IQ tests (100, 90, 75, 140 etc…)
– Level of depression on a depression scale (27, 32, 61 etc)
– Height in inches (60, 50, 57 etc)
– Weight in pounds (98, 198, 298 etc)
– Standing after the short program in figure skating (1, 2, 3
What is a categorical variable
Can take on only one specific value based on
some agreed upon and clear system for assigning
the values
Ex: – Gender for the most part is assigned to each person
based on one value
• 1 female/ 0 male/ 2 transgender OR
• 0 female/ 1 male/ 2 transgender OR
• 0 transgender/ 1 female/ 2 male
What are the type of categorical variables
Ordinal, nominal
What is ordinal
There is a clear ordering of this variable, ordering matters
Ex: Gender:
• 0 male 1 female;
– the 0 and 1 do no indicate some rank or order
– Placement in Olympic ice hockey:
• Canada 1; USA 2; Russia 3;
– Here the numbers indicate a rank
What is nominal
Categorical scale, no intrinsic ordering
What are the types of scales we use to measure variables
ordinal, nominal, interval, ratio
What is an interval scale
There is no real 0 point in such scales; if there is
one it is arbitrary
Ex: IQ: 90, 100, 110
– The difference between 100 and 90 has the same meaning as between
100 and 110 but there is no real 0 (No 0 IQ; i.e. no IQ at all)
• Year of birth: 1992, 1997, 2002
– The difference between 1992 and 1997 is the same as 1997 and 2002 but
there in no real 0 (No 0 year; no year at all)
• Temperature: 50F, 55F, 60F
– The difference between 50 and 55 is the same as 55 and 60
Likert Scale
