Experiments and Double Blinding By Veronica Coronado and Olivia Barth
In order to answer cause and effect questions, we need to create a treatment group and a control group that are alike in every way possible, except that one group gets a treatment and the other does not. This distinguishes an experiment from an observational study. Observation is where they collect data and base their case off of those collections. EXPERIMENT
The four key features of a well designed controlled experiment are: 1.Sample size/Replication 2.Random Selection/Assigned 3.Double Blinded 4.Placebo (if possible)
No 1. Sample Size/Replication The sample size must be large so that there are opportunities to observe the full range of variability in humans, or what ever subject/object being studied. *
No 2. Random Selection: How the sample numbers are collected from a population For Example, the population is our class and we want to randomly select 10 students. To select the 10 students we have many options, including random number generators or using a deck of cards.
No 2. Random Assignment: The subjects of a study must be assigned to the treatment and control groups at random, while trying to keep them nearly alike in every relevant way except whether or not they receive the treatment during the experiment. If both groups have a large enough number of subjects random assignment should balance it out
No 3. Double Blinded If both researchers and participants have no idea which group the subjects are in, the chances of a bias experiment are close to zero.
No 3. cont. To avoid a bias results the study should be “double blinded” Examples of possible bias in an experiment = not conducting a random sample, or treating the “treatment” group differently to get specific results
No 4. Placebo When applicable a study should use a placebo. People often react, not just to a particular medical treatment but also to the idea that they are getting medical treatment. To avoid patients feeling the effects or symptoms of a treatment that they may or may not be getting, a placebo should be used. What is a placebo? a harmless pill, medicine, or procedure, which mimics the treatment to get true results