This helper function constructs a timeline where the order of test elements (or blocks of test elements) is determined at run time.
order_at_run_time( label, get_order, logic, save_order = function(order, state, ...) save_result(state, label, order) )
(Character scalar) A label for storing the generated order of test elements.
Function that should accept the arguments
List where each top-level element corresponds to a randomisation unit. These randomisation units may be either single test elements, lists of test elements, or timelines.
A function called at run time to save the result of
A list of test elements, or equivalently a timeline, which can be combined
with other test elements or timelines.
These test elements will be presented in the order defined by the
get_order function, with this function being called
afresh for each new participant.
This function can be nested arbitrarily many times.
randomise_at_run_time for the common application
of randomising the order of test elements anew for each participant.