What creates complexity when assessing group work?

Evaluating individual contributions can be challenging in group work due to the collaborative nature of tasks. In a group setting, contributions can often be interdependent, meaning that it may be difficult to discern who contributed what to the final product. This can lead to issues such as free-riding, where some members may benefit from the efforts of others without putting in equal effort themselves. Consequently, teachers often struggle to assess how much each individual really contributed to the project's success. This complexity requires careful consideration and sometimes alternative methods, such as peer assessments or individual reflections, to fairly evaluate each student's involvement and learning.

The other aspects presented in the options, while they may touch upon issues related to group assessments, do not directly address the inherent difficulties in assessing individual contributions. They imply situations that may not universally apply to all group work scenarios.