Random assignment: assigning participants to experimental and control conditions by chance Vs. Random sample: a sample that fairly represents a population because each member has an equal chance of being included You decide :-D
Allows for potential confounding
ol
to select a random sample you pick them at random
It might help if you specified why WHAT was important in random variables.
Groups have equal and balanced composition
To get a more accurate estimate of the entire population.
assures that all participants have an equal chance of being assigned to any condition.
That's a random question
sampling is very important for researcher
ol
"A quasi-experimental design is one that looks a bit like an experimental design but lacks the key ingredient -- random assignment." see http://www.socialresearchmethods.net/kb/quasiexp.php
Without random assignment there is a danger of systematic error - or bias - entering into the results. Statistical theory depends on the errors being random and independent error and that is no longer the case without random assignment. In fact, statistical experiments are often "double-blind": even the observer does not know which individual is in which group. This is to prevent unconscious or subconscious messages to affect the outcome (placebo effects).
Participants can be assigned to groups using random assignment, where each individual has an equal chance of being placed in any group, or through matched assignment, where participants are matched on key variables before being assigned to groups. Other methods include stratified random assignment, where participants are grouped based on specific characteristics before random assignment, and block randomization, where participants are assigned to groups in blocks to ensure equal group sizes.
A quasi-experimental research design is a type of research methodology that lacks full experimental control but still allows for comparison between groups. It involves manipulating an independent variable to observe its impact on a dependent variable, but lacks random assignment to groups. This design is often used when true experimentation is not feasible or ethical.
random assignment
Random sampling is the sample group of subjects that are selected by chance, without bias. Random assignment is when each subject of the sample has an equal chance of being in either the experimental or control group of an experiment.