1, coin toss method
The grouping of subjects is decided by flipping a coin. The head represents one group and the tail represents another group. This method is simple, but it may be influenced by external factors such as uneven coins.
Step 2 draw lots
Put the labels with different groups in a container, and the subjects randomly choose a label and determine their groups according to the contents on the label. This method is also very simple, but it needs to ensure the fairness and transparency of the label making and extraction process.
3, touch the ball method
Put balls of different colors or marks into the bag, and each ball represents a group. Subjects touch a ball in turn and determine its grouping according to the properties of the ball. This method is intuitive and clear, but it requires the same texture and size of the ball to avoid deviation.
4. Random number table
Using a randomly generated digital table, the required random numbers are determined according to the number of experimental subjects. Then group according to factors such as quantity or parity. This method has high accuracy and repeatability, but it needs to ensure the quality of the random number generator.
Significance of random grouping
Random grouping is of great significance in scientific experiments and statistics. It ensures that the individuals in the experimental group and the control group are similar in important aspects, thus eliminating potential deviations and interference factors. Through random grouping, we can be more sure that the observed experimental results are caused by processing factors, rather than the initial differences between the experimental group and the control group.
Random grouping is helpful to improve the external validity of the experiment and make the experimental results more general. If there is a significant difference between the experimental group and the control group at the beginning, the experimental results may not be applicable to the target population.
Random grouping can also improve the internal validity of the experiment. If there is no random grouping, people may question the experimental results, because other factors may lead to differences between the experimental group and the control group. Random grouping reduces this worry and makes the experimental results more credible.