I have reviewed my chapter several times and I am not able to answer this question, can you assist me please?

A researcher wants to investigate whether mindfulness training improves ability for employees to notice positive experiences in the workplace, and if this differs by disposition. A factorial design was used to analyze the data. The variables are described below:

Employees were randomly assigned to one of two groups: no training or a half-day session.

Disposition was categorized as follows: optimist, pessimist or realist.

Ability to notice positive experiences in the workplace was quantified using a Likert-based ambulatory assessment.

If there is a main effect of Training, would Tukey's HSD need to be calculated? Why or why not?