It is important to communities that newcomers progress to more valuable tasks. For those who do many easy tasks, we want to nudge them toward trying more difficult tasks. This could happen after they complete a certain number of easy tasks, or by encouragement on their homepage.
If we provide automated prompts at the right moments, we can nudge newcomers into trying different task types and/or more difficult tasks, which should help them progress on their learning journey.
If we provide encouragement and positive reinforcement at the right moments, we can help engage newcomers more, which should help with newcomer retention.