WebExp2 Experimenter's Manual - School of Informatics - University ...

4.7.1 Specifying an order
The first is by specifying an tag within a stage. This is useful if you want to change the ordering in
a deterministic way, i.e. if you know what order you want the slides to be in. The tag makes it easy
for you to do this without reordering slides by hand. You can change the order for testing for example, and
comment out the tag if you want to revert to the natural ordering.
4.7.2 Free randomisation of slides
The second approach is to add a tag to a stage, which tells the client to randomise whatever
sequence of slides it finds in that stage.
Note: Any reordering is output to the results for future reference.
4.8 Randomisation of resources
Another method of randomisation is available if you are importing stimulus resources into your experiment.
You can define the structure of your experiment (sequence of slides, repetitions and so on) and then separately
randomise the resources which you put into that structure.
Currently only free randomisation and blocked randomisation are supported. In future we plan to add constrained
randomisation, along with automatic counterbalancing for conditions.
To randomise a set of resources, you simply add a attribute to the resource set when you import
it. This is described in more detail in section 5.4.4 on importing resources.
Note: Any reordering is output to the results for future reference.
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