We're glad you're so excited about SIP! First thing's first, make sure you're eligible. Are you the correct grade level? If you have already participated in advanced computer science programs (like AP or IB), you are not eligible because SIP is an introductory program.
Second, apply early! Our acceptance rates are higher for earlier round applicants. Put effort into your application, including the short answer question. Lastly, if there are multiple locations that work for you, you will have more options for acceptance, so consider adding other host sites to your application, even if they aren't your first choice. Ultimately, we receive thousands more applications that we can accept for our limited seats. If you are a rising junior and you are not accepted, please consider applying again the following summer!