Glossary - Research Basics and Terminology

• Experiment which compares two or more interventions 
• Intervention is compared to control intervention (= no intervention or another type of intervention)
• Participants for each intervention are randomly assigned
• Common assignment to group: one intervention assigned to each individual
• Cluster-randomization: assignment to defined groups of individuals (e. g. class, household)
• Example:

Randomized-Controlled Trial: Treatment success for patient A with drug A in comparison to treatment success for patient B with already existing drug B

Cluster-Randomised-Controlled Trial: Prevalence of obesity in a community with a systematic physical activity program versus a community without any such program

• Difference between lowest and highest value
  
• Formula: R= Maximum- Minimum
  
• Example:

• Measurement scale; interval known with 0 point
• Type of data: metric, quantitative, discrete or continuous
• Example: BMI, cigarettes per day, age, etc.

• Risk of a certain event happening in one group versus the same event happening in another group
• Usually related to risk factor exposure group versus control group
• Ranges:

• Example: RR= 1.3 for lung cancer in smokers compared to non-smokers

• Reproducibility of a study
• Example:

• Aspect of a subject’s condition, lifestyle or environment that affects the probability of a disease to occur 
• Example: obesity = risk factor for high blood pressure