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

My New Experiment
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The and tags are described in more detail in the following section. Note that images
can be imported in two ways:
• With an tag – this allows you to name images so you can say precisely which image you want
to place into your experiment design, and to use it multiple times. (This is useful for example to show a
logo or repeated reference image.)
• With a tag – in this case your list of images is stored in an external resource file, and when
you want to use an image in your experimental design you refer to the resource set rather than a specific
image. (This is useful when you want to import images as stimuli, and is necessary to randomise the order
of your images.)
Next: Import named image resources
To use particular named images in specific places in your experiment, you will list them in an
preamble at the start of the timeline.
5.3 Image files
If you have a small number of images which you wish to use in specific components in your design, it will be
easiest to use the tag to list them. Note: You can still use resource sets in addition to these images,
for importing randomisable lists of images.
To use image resources, you should define an imagebase element which sets the directory where the images
may be found, and then a list of images you want to use from that directory. Figure 5 shows an example of
importing individual images.
The images element contains a number of elements of the form filename, where name is a name
by which you can refer to the image to include it in your slides, and filename is the full name of the file
containing the image. This file can be a JPEG, PNG or GIF image.
You can later import any of these images repeatedly by defining an image component with a content property
such as earth.
Next: Create external resources
If you are importing your stimulus resources, you will need to a) write some resource files which
list your resources, and b) specify these files in your timeline.
5.4 Resource files
Resource files describe the changeable parts of your experiment – the content. This comprises such things as
images or sentences which you want to present to the subject. It will also include audio files when audio is
implemented. You can include text resources directly in the components of your timeline, using the
property of components. However if your experiment uses a repetitive sequence of similar slides, it would be
more sensible to use resource files, for reasons elaborated in section 5.1.
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