Table 4. Expectations toward rigor in study design.

	All research	Research informing a formal knowledge claim (i.e. research requiring maximal rigor)
Study plan	Should be defined and documented before starting the experiments	Must be defined and documented before starting the experiments
Study hypothesis	Advised to define	Must be pre-specified
Blinding	Advised to implement	Should be implemented, exceptions must be justified and documented
Randomization	Advised to implement	Should be implemented, exceptions must be justified and documented
Sample size calculation	Advised to define and document before starting the experiments	Must be defined and documented before starting the experiments (e.g. included in the study plan)
Data analysis	Advised to define and document before starting the experiments	Must be defined and documented before starting the experiments (e.g. as a formal statistical analysis plan and/or included in the study plan)
Inclusion and exclusion criteria	Advised to define and document before starting the experiments	Must be defined and documented before starting the experiments (e.g. included in the study plan)
Deviations from study plan	Advised to document	Must be documented
Preregistration	-	Should be implemented