Exercise

Null hypothesis testing

Null hypothesis testing uses p-values to test if a variable differs significantly from zero. Recently, the abuse and overuse of null hypothesis testing and p-values has caused the American Statistical Association to issue a statement about the use of p-values.

Because of criticisms such as these and other numerical challenges, Doug Bates (the creator of the lme4 package) does not include p-values as part of his package. Yet, you may still want or need to estimate p-values. To fill this need, several packages exist, including the lmerTest package.

lmerTest uses the same lmer() syntax as the lme4 package, but includes different outputs. During this exercise, you will fit a lmer() model using lmerTest and lme4.

Instructions 1/2

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  • Load the lmerTest package, which will also load the lme4 package.
  • Build a lmer() model using only the lme4 package. In R, this is done with lme4::lmer().
  • Build the same lmer() but use the lmerTest package.
  • Look at each model's summary.