I'm conducting research where participants come into a lab and complete a study entirely on a computer (about 10-15 minutes). This means that informed consent, instructions, manipulations, and measures are all completed on the computer and there is very little experimenter-participant interaction. The studies are mostly reading some text and answering questions.
I'm aware that there are many methods of assessing whether participants are paying attention, but when I use these methods I often find a large share of participants who aren't paying attention. Instead of just having to exclude these participants, I'd like to prevent this in the first place.
What strategies do you use to make online studies more engaging and encourage participants to pay attention?