\BeginKnitrBlock{exercise}\iffalse{-91-83-121-115-116-101-109-97-116-105-99-32-101-114-114-111-114-93-}\fi{}<div class="exercise"><span class="exercise" id="exr:unnamed-chunk-9"><strong>(\#exr:unnamed-chunk-9)  \iffalse (Systematic error) \fi{} </strong></span>Can you think of a systematic error from your own research?</div>\EndKnitrBlock{exercise}