Statistical p-values

When results of studies or research are reported, important decisions are made on the basis of these results. For example, new varieties are often tested against standard varieties to determine if the new varieties is more effective. Several methods of manufacturing may be compared to select the best technique to manufacture the best product. Several evidence may be examined to determine if there is a possible link between one activity and a result....

Cautions about Regression and Correlation

Correlation and regression are powerful tools for describing the relationship between two variables. When you use these tools, you must be aware of their limitations. ■ Correlation and regression lines describe only linear relationships. You can do the calculations for any relationship between two quantitative variables, but the results are useful only if the scatterplot shows a linear pattern. ■ Correlation and least-squares regression lines...