Welcome to Callihan's Cache Tech Challenges. Tech Challenges are an alternative form of PD with a focus on individualized and authentic Professional development. All challenges aim at getting participants to dive right into a tech tool, use it and share their outcome. Tech Challenges allow participants to work on their own time and at their own pace. Once a challenge is posted, there is usually a two-week window for completion. Each challenge gives specific directions and information necessary for success. Challenge entries are also posted on this site. Feel free to browse, try, share and duplicate any of these challenges.