This article introduces the basic knowledge of statistical models and sampling distributions.
What is a statistical model
The statistical model describes the relationship between variables . The black straight line in the figure above is a linear model that describes the relationship between the body and weight of a mouse;
The model is an approximate estimation of the real data . The length of the dashed line in the y-axis direction in the above figure indicates the distance between the model estimate and the real data;
We use a large amount of experimental data to verify whether the model is robust.
What is the sampling distribution
In real life, it is often impossible to directly study the population . It is necessary to randomly select samples to study the distribution of the population. For example, if a batch of 100,000 bulbs are produced, if you want to know the average use time of 100,000 bulbs, you can select 300 randomly. To estimate.
Assuming that both samples are from the same population distribution, p is not significant , and the two samples drawn may come from the same distribution;
Assuming that the two samples are from different population distributions, and p is significant , the two samples drawn may come from different distributions;
Through multiple random sampling, the p value is compared with the sample difference, the probability when p is significant and insignificant can be calculated , and it is further determined whether the sample size can reflect the population.
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