This is the variable that us manipulated by the investigator in a research study
What is an INDEPENDENT VARIABLE?
This threat occurs when observed changes or differences are due to a change in the measuring instrument for the dependent variable
What is INSTRUMENTATION?
A study that compares two groups of people: those with the disease/condition of interest, and a similar group of people who do not have the disease/condition
What is a CASE-CONTROL STUDY?
This step involves selecting and defining your study sample
What is ENROLLMENT?
This research study, which ran from 1932 to 1972 in Alabama, investigated the effects of an untreated STI in a large group of poor, African-American men
What is the TUSKEGEE SYPHILIS STUDY?
This is an experimental method used to ensure impartiality and avoid errors arising from bias
What is DOUBLE-BLINDING?
This threat occurs when some type of physical or mental change occurs naturally over the course of the study and affects participants' performance
What is MATURATION?
A type of research study that follows large groups of people over a very long period of time
What is a LONGITUDINAL STUDY?
This step involves maintaining the study cohort over prolonged periods of time
What is FOLLOW-UP?
This 19th century English anesthesiologist, studied an 1854 outbreak of cholera in London - he also shares a name with a Game of Thrones character
Who is JOHN SNOW?
The degree to which study findings can be generalized to other study populations with different characteristics
What is EXTERNAL VALIDITY?
Another word for mortality, this refers to the loss of participants over the course of a study
What is (DIFFERENTIAL) ATTRITION?
This type of observational study can be prospective or retrospective
What is a COHORT STUDY?
This step involves randomizing participants into trial groups ("trial arms")
What is ALLOCATION?
This area of study is the social scientific description of a people and the cultural basis of their behaviors, attitudes, norms, and beliefs
What is ETHNOGRAPHY?
These are variables through which the intervention causes changes in the trial's outcomes or end points?
What are MEDIATORS?
Also known as the observer effect, this threat refers to a phenomenon whereby participants modify an aspect of their behavior in response to being observed
What is the HAWTHORNE EFFECT?
This type of study evaluations interventions without randomization
What is a QUASI-EXPERIMENTAL STUDY?
This is a critical step that creates a formal record of your design, hypotheses, planned analyses, and dependent variables
What is REGISTRATION?
This type of observational study compares two groups of participants, and calculates odds ratios
What is a CASE-CONTROL STUDY?
These are the variables that may affect the study outcomes and are not of interest to the research question, but may threaten the trial's validity
What are EXTRANEOUS VARIABLES?
This threat occurs when the selection of study participants is based on extreme scores that, when measured again, move back to an average level
What is STATISTICAL REGRESSION?
This method involves segmenting a population into clusters, and then further dividing them into smaller group units across many points
What is MULTI-STAGE CLUSTER SAMPLING?
What is ANALYSIS?
This phenomenon is when a measure of association changes over values of another variable - it is not a confounder
What is EFFECT MEASURE MODIFICATION?