The tools and techniques of quality control are divided into seven old tools (flow chart, cause and effect diagram, histogram, scatter diagram, array diagram, control chart, checklist) and new seven tools (matrix diagram, tree diagram, mutual Relationship diagram, affinity diagram, process decision method diagram, activity network diagram, priority matrix diagram).
A scatter plot is a graph used to represent the relationship between two variables, also known as a correlation graph, which is used to analyze the correlation between two measured values. The greater the correlation between the two variables, the less scattered the points in the graph, and the points tend to be concentrated near a straight line.
Scatter plots have the advantage of being intuitive and simple. The data correlation can be observed intuitively through the scatter plot, which can not only obtain complete conclusions, but also eliminate abnormal data through observation, thereby improving the accuracy of calculating the correlation degree.
In regression analysis, the distribution map of data points on the plane of the rectangular coordinate system, and the scatter diagram represents the general trend of the dependent variable changing with the independent variable, according to which an appropriate function can be selected to fit the data points.
Scatter plots can provide three types of key information:
(1) Whether there is a quantitative correlation trend between variables;
(2) If there is a correlation trend, whether it is linear or curvilinear;
(3) If there is a certain point or points that deviate from it Most points, or outliers, can be seen at a glance with a scatterplot. This allows further analysis of whether these outliers are likely to have a large impact on the population in the modeling analysis.
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2018 is coming, may you rise step by step in the new year and be as happy as a flower!
happy New Year!