‘Random’ means that there is no obvious pattern or predictability in the way items are ordered. Simple randomization is the process of putting anything in a random order.
In a tricot experiment, growers receive trial packages that contain a random sub-set of three technology options. For example, if the tricot focus technology is ‘bean varieties’, every participating grower receives a set of three bean varieties, which are randomly picked from the total pool of bean varieties included in the project. Experience shows that a small share of growers tends to drop out of a tricot project, for different reasons. This is not a problem at the level of the entire project. At the local level, however, this can lead to an imbalance. If technology options are distributed by simple randomization only, some technology options can be rare or absent in a certain community.
To address this issue, the tricot approach uses the ClimMob online software to assign technology options to participating growers using an advanced form of randomization: sequentially balanced randomization. This means that trial packages contain a balanced frequency of each technology option. For example, if we distribute packages 1–10 in the first local community, 11–30 in the second community and 31–40 in the third community, each individual variety will occur with nearly equal frequency within each community. If growers in the first community take only 9 trial packages instead of 10, distribution in the second community can simply start with trial package 10.